HomeMy WebLinkAbout06301-12-01; Spyglass-Elm Avenue; Spyglass Landis Industries, Inc.; 1999-04-28UPDATE
GEOTECHNICAL INVESTIGATION
SPYGLASS
CARLSBAD, CALIFORNIA
PREPARED FOR
LANDIS INDUSTRIES, INC.
ANAHEIM, CALIFORNIA
RECEIVED
MAY 1 1 1999
CITY OF CARLSBAD
PLANNING DEPT.
APRIL 1999
GEOCON
INCORPORATED
GEOTECHNICAL CONSULTANTS
Project No. 06301-12-01
April 28, 1999
Landis Industries, Inc.
5753 East Santa Ana Canyon Road, Suite G
Anaheim, California 92807
Attention:
Subject:
Gentlemen:
Mr. John L. Wismer
SPYGLASS
CARLSBAD, CALIFORNIA
UPDATE GEOTECHNICAL INVESTIGATION
In accordance with your authorization and our proposal dated April 12, 1999, we have reviewed and
updated our original study for the subject project entitled Geotechnical Investigation and Geologic
Reconnaissance [for] Spyglass-Elm Avenue, Carlsbad, California, dated July 17, 1989 (Project
No. D-4394-J01). In addition a site reconnaissance was performed on April 8, 1999, at which time it
was observed that the site remains essentially unchanged since the submittal of the original report.
The accompanying report presents the results of our study and conclusions and recommendations
pertaining to developing the property as presently proposed. Provided the recommendations of this
report are followed, the site is considered suitable for development as currently planned.
Should you have any questions regarding this report, or if we may be of further service, please
contact the undersigned at your convenience.
Very truly yours,
GEQCPN INCQ:
AS:DFL:dmc
(6) Addressee
CERTIFIED
ENGINEERING
GEOLOGIST
08/31/99
6960 Flanders Drive • San Diego, California 92121-2974 • Telephone (619) 558-6900 • Fax (619) 558-6159
TABLE OF CONTENTS
1. PURPOSE AND SCOPE 1
2. SITE AND PROJECT DESCRIPTIONS 1
3. SOIL AND GEOLOGIC CONDITIONS 2
3.1. Fill(Qaf) 2
3.2. Colluvium/Topsoil (Unmapped) 2
3.3. Alluvium (Qal) 3
3.4. Santiago Formation (Ts) 3
4. GROUNDWATER 3
5. STRUCTURE 3
6. GEOLOGIC HAZARDS 4
6.1. Faulting and Seismicity 4
6.2. Seismic Design Criteria 5
6.3. Liquefaction 5
6.4. Landslides 5
7. CONCLUSIONS AND RECOMMENDATIONS 6
7.1. General 6
7.2. Soil and Excavation Characteristics 6
7.3. Grading 6
7.4. Subdrains 8
7.5. Slope Stability 8
7.6. Earthwork Grading Factors 9
7.7. Foundation Recommendations 9
7.8. Retaining Walls and Lateral Loads 13
7.9. Slope Maintenance 14
7.10. Drainage 15
7.11. Plan Review 15
LIMITATIONS AND UNIFORMITY OF CONDITIONS
MAPS AND ILLUSTRATIONS
Figure 1, Vicinity Map
Figure 2, Geologic Map (Map Pocket)
Figure 3, Typical Subdrain Detail
Figure 4, Typical Stability Fill Detail
Figure 5 Cut Slope Stability Analysis
Figure 6, Fill Slope Stability Analysis
Figure 7, Surficial Slope Stability Analysis
TABLE OF CONTENTS (Continued)
APPENDIX A
FIELD INVESTIGATION
Figures A-l-A-10, Logs of Borings
Figures A-l l-A-23, Logs of Trenches
APPENDIX B
LABORATORY TESTING
Table B-I, Summary of Laboratory Maximum Dry Density and Optimum Moisture
Content Test Results
Table B-II, Summary of Direct Shear Test Results
Table B-III, Summary of Laboratory Expansion Index Test Results
APPENDIX C
RECOMMENDED GRADING SPECIFICATIONS
UPDATE GEOTECHNICAL INVESTIGATION
1. PURPOSE AND SCOPE
This report presents the results of a geotechnical investigation for the Spyglass Property located at
the southeast corner of the intersection of El Camino Real and Carlsbad Village Drive, in Carlsbad,
California (see Vicinity map, Figure 1). The purpose of the investigation was to evaluate the surface
and subsurface soil and geologic conditions encountered and to provide recommendations pertaining
to the geotechnical aspects of future development.
The scope of the geotechnical investigation included a review of the following:
1. Geotechnical Investigation and Geologic Reconnaissance for Spyglass Elm Avenue,
Carlsbad, California, prepared by Geocon Incorporated, dated July 17, 1989.
2. Geologic Maps of the Northwestern Part of San Diego County, California, prepared by
California Division of Mines and Geology, 1996 (DMG Open File Report 96-2).
3. Tentative Map, Carlsbad, California, prepared by Tail Consulting, undated.
4. Unpublished reports, aerial photographs and maps on file with Geocon Incorporated.
The scope of the field investigation consisted of a geologic reconnaissance and the excavation of 4
large-diameter exploratory borings and excavation of 13 trenches. Logs of the exploratory
excavations are presented in Appendix A. The approximate locations of the exploratory excavations
are depicted on the Geologic Map (Figure 2).
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,
respectively.
The recommendations presented herein are based upon an analysis of the data obtained in the
referenced report, observations during this investigation and our experience with similar soil and
geologic conditions.
2. SITE AND PROJECT DESCRIPTIONS
The site consists of approximately 10.4 acres of undeveloped land at the southeast corner of the
intersection of El Camino Real and Carlsbad Village Drive in Carlsbad, California (see Vicinity Map,
Figure 1). The site is triangular in shape and generally slopes downward moderately to steeply to the
west. An alluvial filled drainage which trends east-west crosses the site on the southern half. The
future extension of Appian Road is proposed to continue from the south side of the site to its northern
Project No. 06301 -12-01 - 1 - April 28, 1999
terminus at the intersection with Carlsbad Village Drive. Additional interior site access will be
provided by a cul-de-sac extending from Appian Road towards the east. An existing slope inclined at
approximately 1:1 (horizontal to vertical) is located along portions of El Camino Real and an existing
slope inclined at approximately 2:1 bounds a portion of Carlsbad Village Drive. Several other natural
and graded slopes of varying heights and inclinations bound the eastern side of the site adjacent to the
existing residential development. Previous site grading included the cutting of a relatively flat pad at
the intersection of Carlsbad Village Drive and El Camino Real.
The referenced plans indicate that the site will be graded for 19 single-family residential building pads.
Elevations within the site range from a low of approximately 136 feet Mean Sea Level (MSL) in the
northwest corner of the site to a high of approximately 270 feet MSL in the northeast corner of the site.
A major slope will be graded along El Camino Real at an inclination of 2:1 or flatter and a maximum
height on the order of 50 feet. Similar size slopes will be constructed along portions of Carlsbad
Village Drive. Maximum cuts and fills on the order of 25 feet and 50 feet, respectively, are proposed.
3. SOIL AND GEOLOGIC CONDITIONS
Three surficial soil types and one geologic formation exist at the subject property. The surficial units
include undocumented fill, topsil, and alluvium. The geologic unit encountered is the Eocene-aged
Santiago Formation. Each of the soil types and geologic formations is discussed below in order of
increasing age. Their estimated areal extent is shown on the Geologic Map, Figure 2 (map pocket).
The limits of the colluvium is not shown since it covers most of the site as a thin veneer.
3.1. Fill(Qaf)
Several minor areas of previously placed fill soils were encountered during the field investigation.
The fills appear to have been associated with prior site gradirig including the placement of the
adjacent subdivision and storm drain trench backfill. The fills soils observed were typically very
shallow and consisted of mixtures of the onsite materials, which are predominantly silty sands and
clays. The fill soils were generally loose and should not be considered suitable to support either
additional fill soils or settlement sensitive improvements in their present condition due to their
compressibility characteristics. Remedial recommendations are provided under the Conclusions and
Recommendations section of this report.
3.2. Colluvium/Topsoil (Unmapped)
Colluvium/topsoil covers most of the natural areas of the site. The colluvium/topsoil is typically a
thin layer of less than 2 feet in thickness. These materials observed ranged from a dense, humid, light
brown silty fine to coarse sand to a stiff, moist, dark brown sandy clay. The colluvium/topsoil is not
Project No. 06301-12-01 - 2 - April 28, 1999
considered suitable to receive either additional fill soils or to support settlement sensitive
improvements in their present condition due to their low moisture content and compressibility
characteristics.
3.3. Alluvium (Qal)
Alluvial soils were encountered in the drainage which crosses the southern half of the site. The
alluvial soils in the drainage average approximately 10 feet in thickness with a maximum of 15 feet
encountered in Trench T-6. Localized deeper areas may be present. These soils typically consisted
of dense, slightly moist, brown to grey, silty and clayey sands and were often mottled and porous.
The alluvial soils will require removal and recompaction in areas where settlement sensitive
improvements are proposed.
3.4. Santiago Formation (Ts)
Eocene-aged Santiago Formational soils were found to underlay the site. Silty or clayey sandstones
are predominant in the formation with interbedded clayey siltstones and silty claystones. The
materials are typically dense to very dense, slightly moist to moist, and should be suitable bearing
soils in either a natural or a properly recompacted condition. Portions of this formation may be
expansive and are not recommended for use at finish pad grade with standard foundations or within
the outer 15 feet of fill slopes.
4. GROUNDWATER
No groundwater was encountered during the field investigation, however, seepage was observed in
Boring No. B-4 at approximately 34 feet below existing ground surface. During the recent site
reconnaissance, seepage was observed at the toe of the existing slope along the southwest corner of
the site. Due to the interbedded claystones and siltstones within the very permeable sandstones it is
likely that seasonal seeps, perched water tables and ponding water problems may result due to
increased precipitation and irrigation. It is anticipated that seepage may be encountered during
grading depending on when grading is performed. Remedial grading recommendations are provided
later in this report. Due to the granular nature of much of the material on the site it is anticipated that
seasonal water will migrate throughout the site drainages and therefore canyon subdrains should be
installed during grading as outlined in the Conclusions and Recommendations.
5. STRUCTURE
Regionally the Santiago Formation has a west to southwest dip of several degrees which may affect
the stability of the proposed slopes, Locally observed bedding in the borings was predominantly
Project No. 06301 -12-01 - 3 - April 28, 1999
northwest dipping and will require that all cut slopes be observed and mapped during grading to
determine if stability or buttress fills are required.
6. GEOLOGIC HAZARDS
6.1. 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 faults are the Rose Canyon and Newport-Inglewood Fault Zones located
approximately 6 miles northwest and west of the site. Maximum Credible and Maximum Probable
seismic events of Magnitude 6.9 and Magnitude 5.7, respectively, are postulated for the these fault
zones.
The estimated Maximum Credible and Maximum Probable peak site accelerations are 0.25 g and
0.13 g, respectively. The maximum effective ground motion, however, is estimated to be
approximately 0.18 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 other regional faults capable of
generating ground acceleration at the site are summarized below.
TABLE 6.1.
DETERMINISTIC SITE PARAMETERS FOR SELECTED FAULTS*
Fault Name
Compton Thrust
Elsinore- Julian
Elsinore-Temecula
Coronado Bank
Newport-Inglewood (offshore)
Rose Canyon
Distance
From Site
(miles)
56
23
23
23
6
6
Maximum Credible Event
Maximum
Credible
(Mag.)
6.8
7.1
6.8
7.4
6.9
6.9
Peak Site
Acceleration
(g)
0.09
0.11
0.10
0.14
0.25
0.25
Maximum Probable Event
Maximum
Probable
(Mag.)
5.8
6.4
6.3
6.3
5.8
5.7
Peak Site
Acceleration
(g)
0.05
0.08
0.08
0.08
0.14
0.13
*EQ Fault Computer Program, Blake, 1996 (CDMG data file).
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.
Project No. 06301-12-01 -4-April 28, 1999
6.2. Seismic Design Criteria
The following table summarizes site-specific seismic design criteria obtained from the 1997 Uniform
Building Code (UBC). The values listed in Table 6.2 are for the Rose Canyon Fault (located
approximately 6 miles west of the site) which is identified as a Type B fault and is more dominant
than the nearest Type A fault (Elsinore) due to its close proximity to the site.
TABLE 6.2
SEISMIC DESIGN PARAMETERS
Parameter
Seismic Zone Factor, Z
Soil Profile Type
Seismic Coefficient, Ca
Seismic Coefficient, Cv
Near-Source Factor, Na
Near-Source Factor, Nv
Seismic Source
Value
0.40
Sc
0.40
0.56
1.0
1.0
B
UBC Reference
Table 16-1
Table 16-J
Table 16-Q
Table 16-R
Table 16-S
Table 16-T
Table 16-U
6.3. 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, and the lack of a permanent groundwater table,
the potential for liquefaction of the site subsoils is considered to be very low.
6.4.Landslides
No landslides or indications of landslides were noted during our field investigations on the site or
immediately adjacent to the site. No indications of landslides were noted on the aerial photographs
reviewed.
Project No. 06301-12-01 -5-Aprii 28, 1999
7. CONCLUSIONS AND RECOMMENDATIONS
7.1. General
7.1.1. 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 this report are followed.
7.1.2. The surficial soils such as undocumented fill soils, topsoil, and alluvium within areas of
planned development are not considered suitable for support of structural fill or structural
loads in their present condition and will require remedial grading in the form of removal
and recompaction. Also the debris and trash will need to be removed and disposed of
off-site.
7.2. Soil and Excavation Characteristics
7.2.1. The prevailing soil conditions encountered during the field exploration consisted of low-
expansive sands derived from portions of the surficial soils and the sandy portion of the
Santiago Formation. The fine-grained surficial soils and siltstones and claystones of the
Santiago Formation possess medium to high expansion potential.
7.2.2. 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.
7.2.3. Deeper alluvial soils may be very moist to saturated during the winter or early spring
depending on the preceding precipitation and may require mixing with drier materials or
drying prior to their use as compacted fill.
7.3. Grading
7.3.1. 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.
7.3.2. 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.
Project No. 06301-12-01 - 6 - April 28, 1999
7.3.3. Site preparation should begin with the removal of all deleterious material and vegetation.
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.
7.3.4. Except as noted below, all compressible surficial soil deposits (undocumented fill, topsoil,
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. Removals
along the edge of grading should include excavation of unsuitable soils that would
adversely affect the performance of the planned fill, i.e., extend removals within a zone
defined by a line project down and out at a slope of 1:1 from the limit of grading to
intersect with firm natural ground except where limited by project boundary constraints.
7.3.5. The actual extent of unsuitable soil removals will be determined in the field during grading
by the soil engineer and/or engineering geologist.
7.3.6. After removal of unsuitable materials as recommended above, 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. Fill materials with in-place density test results
indicating moisture contents less than optimum will require additional moisture
conditioning before placing additional fill.
7.3.7. To reduce the potential for differential settlement, it is recommended that the cut portion of
cut/fill transition building pads be undercut at least 3 feet and replaced with properly
compacted low expansive fill soils. The undercut should extend from the back of the pad
to the street and be graded at a gradient of at least 1 percent towards the street.
7.3.8. Grading operations should be scheduled so as to permit the placement of oversized rock
and expansive soils in the deeper fills and to cap the building pads with at least 3 feet of
granular materials having a low expansive potential (Expansion Index less than 50 per
UBC Table 18-I-B). Oversized rock, if encountered, should be placed at least 10 feet
below finish grade or 3 feet below the deepest utility, whichever is greater.
Project No. 06301 -12-01 - 7 - April 28, 1999
7.4. Subdrains
7.4.1. A subdrain should_be installed within the pagt-wegt-tren^'"g Drainage *n hp filled. The
subdrain should be installed with the upstream end at a minimum of 10 feet below the
proposed finished grades. A cross-section of the recommended subdrain configuration is
presented on Figures. Due to the depth of removals near the west property line, the
subdrain may require outlettin^ to the storm drain planned for the northwest corner of the
site. After installation of the subdrain, the project civil engineer should survey its location
and elevation and prepare "as-built" plans of subdrain locations.
7.5. Slope Stability
7.5.1. The results of the investigation indicate a seepage condition within the southwest corner of
the property. It is recommended that the planned cut slope facing El Camino real be
constructed as a drained stability fill. This will allow installation of a drainage system
(drainage panels and heel drain) to intercept seepage water within the fill slope and
mitigate the adverse affect of water seeping through the slope. A typical stability fill detail
is shown on Figure 4.
7.5.2. The results of analyses indicate that cut and fill slopes have a factor of safety in excess of
1.5 for the maximum anticipated heights (see Figures 5 and 6). Surficial slope stability
analysis of fill slopes also indicates a factor of safety in excess of 1.5 (see Figure 7).
7.5.3. It is recommended that all cut slopes be observed during grading by an engineering
geologist to verify that the soil and geologic conditions do not differ significantly from
those anticipated and to determine if adverse bedding, fractures or joints exist. Remedial
grading procedures can be recommended should adverse geologic conditions be observed.
7.5.4. 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.
7.5.5. 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.
7.5.6. In our opinion, the use of terrace drains on cut or fill slopes exceeding 30 feet in height isffnot:
nggessarytp maintain gross stability of the slopes. It is our opinion, that on the cut slopes
proposed the addition of benches will increase slope heights and surface area without
Project No. 06301-12-01 - 8 - April 28, 1999
providing any significant effect on erosion control. If used, it is recommended that the
terrace drains be constructed at a drainage gradient of at least 5 percent. In addition, the need
to properly maintain the drains is important. Drains which are not periodically cleaned of
vegetation and debris could result in significant slope distress and erosion.
7.5.7. All slopes should be planted, drained and properly maintained to reduce erosion.
7.6. Earthwork Grading Factors
7.6.1. Estimates of embankment shrink-swell factors are based on comparing laboratory
compaction tests with the density of the material in its natural state and experience with
similar soil types. It should be emphasized that variations in natural soil density, as well as
in compacted fill, render shrinkage value estimates very approximate. As an example, the
contractor can compact fills to any relative compaction of 90 percent or higher of the
laboratory maximum dry density. Thus, the contractor has at least a 10 percent range of
control over the fill volume. Based on our experience and laboratory testing in similar
geologic materials, the following earthwork factors may be used as a basis for estimating
how much the on-site soils may shrink or swell when removed from their natural state and
placed in compacted fills. It is recommended that the grading be monitored during
earthwork operations and that a balance area be designated to provide adjustments to the
cut/fill as necessary.
TABLE 7.6.
Soils Unit
Fill Soils, Topsoil,and Alluvium
Santiago Formation
Shrink-Swell Factors
5% to 10% Shrinkage
2% to 10% Bulk
7.7. Foundation Recommendations
7.7.1. The following foundation recommendations are for one-and/or two-story structures and are
based upon the assumption that the soil conditions within 3 feet of finish pad subgrade
consist of granular "low" expansive soil (Expansion Index less than 50). The
recommendations are separated into categories dependent upon the depth and geometry of
fill underlying a particular building pad and/or lot and where alluvium left-in-place may
influence the performance of improvements. Final foundation design recommendations for
each building will be presented in the final compaction report after the grading for the
individual building pads has been completed.
Project No. 06301-12-01 -9-April 28, 1999
TABLE 7.7.1.
FOUNDATION RECOMMENDATIONS BY CATEGORY
Foundation
Category
I
II
III
Minimum
Footing
Depth
(inches)
12
18
24
Continuous Footing
Reinforcement
One No. 4 bar top and bottom
Two No. 4 bars top and bottom
Two No. 5 bars top and bottom
Interior Slab
Reinforcement
6 x 6 - 10/10 welded wire mesh
at slab mid-point
No. 3 bars at 24 inches on
center, both directions
No. 3 bars at 18 inches on
center, both directions
CATEGORY CRITERIA
Category I: Maximum fill thickness is less than 20 feet and Expansion Index is less than or
equal to 50.
Category II: Maximum fill thickness is less than 50 feet and Expansion Index is less than or
equal to 90, or variation in fill thickness is between 10 feet and 20 feet.
Category III: Fill thickness exceeds 50 feet, or variation in fill thickness exceeds 20 feet, or
Expansion Index exceeds 90, but is less than 130, or underlain by alluvium left-in-
place (zone of influence).
Notes:
1. All footings should have a minimum width of 12 inches.
2. Footing depth is measured from lowest adjacent subgrade (including topsoil, if planned). These
depths apply to both exterior and interior footings.
3. All interior living area concrete slabs should be at least 4 inches thick for Categories I and II
and 5 inches thick for Category III. This applies to both building and garage slabs-on-grade.
4. All interior concrete slabs should be underlain by at least 4 inches (3 inches for Category IE) of
clean sand or crushed rock.
5. All slabs expected to receive moisture sensitive floor coverings or used to store moisture
sensitive materials should be underlain by a vapor barrier covered with at least 2 inches of the
clean sand recommended in No. 4 above.
7.7.2. Foundations for either Category I, II, or III may be designed for an allowable soil bearing
pressure of 2,000 pounds per square foot (psf) (dead plus live load). This bearing pressure
may be increased by one-third for transient loads such as wind or seismic forces.
7.7.3. The use of isolated footings which are located beyond the perimeter of the building and
support structural elements connected to the building is not recommended for Category III.
Where this condition cannot be avoided, the isolated footings should be connected to the
building foundation system with grade beams.
Project No. 06301-12-01 -10-April 28, 1999
7.7.4. For Foundation Category III, the structural slab design should consider using interior
stiffening beams and connecting isolated footings and/or increasing the slab thickness. In
addition, consideration should be given to connecting patio slabs, which exceed 5 feet in
width, to the building foundation to reduce the potential for future separation to occur.
7.7.5. No special subgrade preparation is deemed necessary prior to placing concrete, however,
the exposed foundation and slab subgrade soils should be sprinkled, as necessary, to
maintain a moist soil condition as would be expected in any such concrete placement.
7.7.6. Where buildings or other improvements are planned near the top of a slope steeper than 3 : 1
(horizontal :vertical), special foundations and/or design considerations are recommended
due to the tendency for lateral soil movement to occur.
• For fill slopes less than 2QJggt-high, building footings should be deepened such
that the bottom outside edge of the footing is at least 7 feet horizontally from the
face of the slope.
Where the height of the fill slope exc-af?ds ?n fest the pi'nimiirn JinriTinptal
should be increased ta-H/3-(iiihfire H equals the vertical distance from the top of
the slope to the toe) but need not exceed dO feet For composite (fill over cut)
slopes, H equals the vertical distance from the top of the slope to the bottom of the
fill portion of the slope. An acceptable alternative to deepening the footings would
be the use of a post-tensioned slab and foundation system or increased footing and
slab reinforcement. Specific design parameters or recommendations for either of
these alternatives can be provided once the building location and fill slope
geometry have been determined.
For cut slopes in dense formational materials, or fill slopes inclined_at 3:1 j(hori-
zontal:vertical) or flatter, the bottom outside edge of building footings should be at
least_7^feet horizontally fromjhgja££jo£4be-stepe, regardless of "Slope height.
Swimming pooJsJacated within 7 feet of the top of cut or fill slopes are not
recommended. Where such a condition cannot be avoided, it is recommended that
the pbrtionof the swimming pool wall within 7 feet of the slope face be designed
assuming that the adjacent soil provides no lateral support. This recommendation
applies toJULslopes up to 30 feet in height and cut slopes regardless of height. For
swimming pools located near the top of fill slopes greater than 30 feet in height,
additional recommendations may be required and Geocon Incorporated should be
contacted for a review of specific site conditions.
Although other improvements which are relatively rigid or brittle, such as concrete
flatwork or masonry walls may experience some distress if located near the top of a
slope, it is generally not economical to mitigate this potential. It may be possible,
however, to incorporate design measures which would permit some lateral soil
movement without causing extensive distress. Geocon Incorporated should be
consulted for specific recommendations.
Project No. 06301-12-01 - 11 - April 28, 1999
7.7.7. As an alternative to the foundation recommendations for each category, consideration
should be given to the use of post-tensioned concrete slab and foundation systems for the
support of the proposed structures. The post-tensioned systems should be designed by a
structural engineer experienced in post-tensioned slab design and design criteria of the
Post-Tensioning Institute (UBC Section 1816). Although this procedure was developed for
expansive soils, it is understood that it can also be used to reduce the potential for
foundation distress due to differential fill settlement. The post-tensioned design should
incorporate the geotechnical parameters presented on the following table entitled Post-
Tensioned Foundation System Design Parameters for the particular Foundation Category
designated.
TABLE 7.7.2.
POST-TENSIONED FOUNDATION SYSTEM DESIGN PARAMETERS
Post-Tensioning Institute (PTI)
Design Parameters
1 . Thornthwaite Index
2. Clay Type - Montmorillonite
3. Clay Portion (Maximum)
4. Depth to Constant Soil Suction
5. Soil Suction
6. Moisture Velocity
7. Edge Lift Moisture Variation Distance
8. Edge Lift
9. Center Lift Moisture Variation Distance
10. Center Lift
Foundation Category
I
-20
Yes
30%
7.0ft.
3.6ft.
0.7 in./mo.
2.6ft.
0.41 in.
5.3ft.
2. 12 in.
II
-20
Yes
50%
7.0ft.
3.6ft.
0.7 in./mo.
2.6ft.
0.78 in.
5.3ft.
3.21 in.
Ill
-20
Yes
70%
7.0ft.
3.6ft.
0.7 in./mo.
2.6ft.
1.15 in.
5.3ft.
4.74 in.
7.7.8. UBC Section 1816 uses interior stiffener beams in its structural design procedures. If the
structural engineer proposes a post-tensioned foundation design method other than UBC
Section 1816, it is recommended that interior stiffener beams be used for Foundation
Categories II and III. The depth of the perimeter foundation should be at least 12 inches
for Foundation Category I. Where the Expansion Index for a particular building pad
exceeds 50 but is less than 91, the perimeter footing depth should be at least 18 inches; and
where it exceeds 90 but is less than 130, the perimeter footing depth should be at least 24
inches. Geocon Incorporated should be consulted to provide additional design parameters
as required by the structural engineer.
7.7.9. The recommendations of this report are intended to reduce the potential for cracking of
slabs due to expansive soils (if present), differential settlement of deep fills or fills of
Project No. 06301-12-01 - 12-April28, 1999
varying thicknesses. However, even with the incorporation of the recommendations
presented herein, foundations, stucco walls, and slabs-on-grade placed on such conditions
may still exhibit some cracking due to soil movement and/or shrinkage. The occurrence of
concrete shrinkage cracks is independent of the supporting soil characteristics. Their
occurrence may be reduced and/or controlled by limiting the slump of the concrete, proper
concrete placement and curing, and by the placement of crack control joints at periodic
intervals, in particular, where re-entry slab corners occur.
7.8. Retaining Walls and Lateral Loads
7.8.1. Retaining walls not restrained at the top and having a level backfill surface should be
designed for an active soil pressure equivalent to the pressure exerted by a fluid density
of 30 pounds per cubic foot (pcf). Where the backfill will be inclined at no steeper than 2.0
to 1.0, an active soil pressure of 40 pcf is recommended. These soil pressures assume that
the backfill materials within an area bounded by the wall and a 1:1 plane extending upward
from the base of the wall possess an Expansion Index of less than 50. For those lots with
finish grade soils having an Expansion Index greater than 50 and/or where backfill
materials do not conform to the above criteria, Geocon Incorporated should be consulted
for additional recommendations.
7.8.2. Unrestrained walls are those that are allowed to rotate more than 0.001H at the top of the
wall. Where walls are restrained from movement at the top, an additional uniform pressure
of 7H psf (where H equals the height of the retaining wall portion of the wall in feet)
should be added to the above active soil pressure.
7.8.3. All retaining walls should be provided with a drainage system adequate to prevent the
buildup of hydrostatic forces and should be waterproofed as required by the project
architect. The use of drainage openings through the base of the wall (weep holes, etc.) is
not recommended where the seepage could be a nuisance or otherwise adversely impact the
property adjacent to the base of the wall. The above recommendations assume a properly
compacted granular (Expansion Index less than 50) backfill material with no hydrostatic
forces or imposed surcharge load. If conditions different than those described are
anticipated, or if specific drainage details are desired, Geocon Incorporated should be
contacted for additional recommendations.
7.8.4. In general, wall foundations having a minimum depth and width of one foot may be
designed for an allowable soil bearing pressure of 2,000 psf, provided the soil within 3 feet
below the base of the wall has an Expansion Index of less than 90. The proximity of the
foundation to the top of a slope steeper than 3:1 could impact the allowable soil bearing
Project No. 06301-12-01 -13 - April 28, 1999
pressure. Therefore, Geocon Incorporated should be consulted where such a condition is
anticipated.
7.8.5. For resistance to lateral loads, an allowable passive earth pressure equivalent to a fluid
density of 300 pcf is recommended for footings or shear keys poured neat against properly
compacted granular fill soils or undisturbed natural soils. The allowable passive pressure
assumes a horizontal surface extending at least 5 feet or three times the surface generating
the passive pressure, whichever is greater. The upper 12 inches of material not protected
by floor slabs or pavement should not be included in the design for lateral resistance. An
allowable friction coefficient of 0.4 may be used for resistance to sliding between soil and
concrete. This friction coefficient may be combined with the allowable passive earth
pressure when determining resistance to lateral loads.
7.8.6. The recommendations presented above are generally applicable to the design of rigid
concrete or masonry retaining walls having a maximum height of 8 feet. In the event that
walls higher than 8 feet or other types of walls are planned, such as crib-type walls, Geocon
Incorporated should be consulted for additional recommendations.
7.9. Slope Maintenance
7.9.1. Slopes that are steeper than 3:1 (horizontahvertical) 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.
Project No. 06301 -12-01 -14 - April 28, 1999
^ 7.10. Drainage
7.10.1. Establishing proper drainage is imperative to reduce the potential for differential soil
^ movement, erosion and subsurface seepage. Positive measures should be taken to properly
finish grade the building pads after structures and other improvements are in place, so that
drainage water from the building pads and adjacent properties is directed to streets away
*** from foundations and tops of slopes. 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
•*m irrigation.
tit*
"" 7.11. Plan Review
«»
7.11.1. 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. In
*•• addition, the geotechnical engineer should review the structural foundation plans to verify
4W general conformance with the recommendations of this report.
Project No. 06301-12-01 - 15 - April 28, 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. 06301-12-01 April 28, 1999
^~"~SQdSv ;•» 3 **--•— f^ \/ 0\ \2»«**LX>.// >»£. \*-•f-:- :gU>.^> --';s~ • . JV>- / S\ a^TTc ^At^ft"^-.-^
>^ '^M^^^\^& W^-&&$§? ^> ts ^yil)M^S*^^s^) ^-r:' ^ ^^%J
l>^^^^ *# / ^P
TBI,jvr^ \^' iir^- y®'/" *' 1 - i^k. <AT ic. <=• c?*^S•$^* I:^^^^/J^^^TW^' *'G -
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
INCORPORATED
GEOTECHNICAL CONSULTANTS
6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121-2974
PHONE 619 558-6900 - FAX 619 558-6159
VICINITY MAP
SPYGLASS
CARLSBAD, CALIFORNIA
AS/TA DSK/EOOOD DATE 04-28-1999 PROJECT NO. 06301 - 12 - 01 FIG. 1
1VICMAP
APPROVED FILTER FABRIC
6" DIA. PERFORATED
SUBDRAIN PIPE
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 ^SKr
GEOTECHNICAL CONSULTANTS
6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121 • 2974
PHONE 619 558-6900 - FAX 619 558-6159
AS/TA DSK/EOOOO
SPYGLASS
CARLSBAD, CALIFORNIA
DATE 04-28-1999 PROJECT NO. 06301 - 12 - 01 FIG. 3
3D / IXVIII / RSS
FINISHED LOT GRADE
10'
MIN.
FORMATIONAL
SOIL
FINISHED SLOPE
NOTE 2
FINISHED GRADE
FORMATIONAL
SOIL
NO SCALE
NOTES:
1 EXCAVATE BACKCUT AT 1:1 INCLINATION
2 BASE OF STABILITY FILL TO BE 3 FEET INTO DENSE, FORMATIONAL SOILS SLOPING
A MINIMUM 5% INTO SLOPE.
3.... BUTTRESS FILL TO BE COMPOSED OF PROPERLY COMPACTED GRANULAR SOIL WITH MINIMUM
SHEAR STRENGTH OF 0 = 25°, C'= 250 psf
4 WHERE SEEPAGE IS ENCOUNTERED IN BACKCUT, CHIMNEY DRAINS TO BE APPROVED PREFABRICATED
CHIMNEY DRAIN PANELS (MIRADRAIN, TENSAR, OR EQUIVALENT) SPACED APPROXIMATELY 30 FEET
CENTER TO CENTER. ADDITIONAL DRAINS WILL BE REQUIRED WHERE AREAS OF GREATER SEEPAGE
ARE ENCOUNTERED.
5 FILTER MATERIAL TO BE 1-INCH, OPEN-GRADED CRUSHED ROCK ENCLOSED IN APPROVED FILTER FABRIC
6 COLLECTOR PIPE TO BE 4-INCH MINIMUM DIAMETER, PERFORATED, THICK-WALLED PVC SDR 21 OR
EQUIVALENT, AND SLOPED TO DRAIN AT 1 PERCENT MINIMUM TO APPROVED OUTLET.
CHIMNEY DRAINS MAY BE REQUIRED IF AREAS OF ACTIVE SEEPAGE ARE ENCOUNTERED
7. IF HORIZONTAL EXTENT OF GRADING CONSTRAINED (e.g., THE PRESENCE OF PROPERTY LINE). THE SLOPE
SHOULD BE OVERBUILT, AT LEAST 4 FEET, AND TRIMMED BACK
TYPICAL STABILITY FILL DETAIL
GEOCON O
INCORPORATED ^Mr
GEOTECHNICAL CONSULTANTS
6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121-2974
PHONE 619 558-6900 - FAX 619 558-6159
AS/TA DSK/GTYP1
SPYGLASS
CARLSBAD, CALIFORNIA
DATE: 04-28-1999 PROJECT N0.06301 -12-01 FIG. 4
STABFIL6 /DFL/IX/IXVIIIRSS
PROJECT NO. 06301-12-01
ASSUMED CONDITIONS:
Slope Height
Slope Inclination
Total Unit Weight of Soil
Angle of Internal Friction
Apparent Cohesion
No Seepage Forces
H = 40 feet
2:1 (Horizontal: Vertical)
yt = 130 pounds per cubic foot
<j) = 27 degrees
C = 440 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)
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.
CUT SLOPE STABILITY ANALYSIS
SPYGLASS
CARLSBAD, CALIFORNIA
FIGURES
PROJECT NO. 06301-12-01
ASSUMED CONDITIONS:
Slope Height
Slope Inclination
Total Unit Weight of Soil
Angle of Internal Friction
Apparent Cohesion
No Seepage Forces
H = 55 feet
2:1 (Horizontal:Vertical)
yt = 125 pounds per cubic foot
<j> = 30 degrees
C = 250 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)
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
SPYGLASS
CARLSBAD, CALIFORNIA
FIGURE 6
PROJECT NO. 06301-12-01
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 y, = 125 pounds per cubic foot
Angle of Internal Friction (j> = 30 degrees
Apparent Cohesion C = 250 pounds per square foot
Slope saturated to vertical depth Z below slope face.
Seepage forces parallel to slope face
ANALYSIS:
ytZsmicosi
= 2.2
REFERENCES:
(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
SPYGLASS
CARLSBAD, CALIFORNIA
FIGURE?
1 APPENDIX
I
I
I
I
I
I
I
I
APPENDIX A
FIELD INVESTIGATION
The field investigation was performed during June 23, 26 and 27, 1989 and consisted of and the
excavation of 4 exploratory borings and 13 exploratory trenches at the approximate locations shown
on the Site Plan, Figure 1. The borings were advanced to depths ranging from 47 to 70 feet below
existing grade with a 30-inch bucket auger. Relatively undisturbed samples were obtained from the
borings by driving a 3-inch split-tube sampler 12 inches into the undisturbed soil mass with blows
from drill rig Kelly bar falling 12 inches. The sampler was equipped with 1-inch by 2Vs-inch brass
sampler rings to facilitate removal and testing.
The trenches were excavated utilizing a John Deere 555 Track Backhoe with 24-inch bucket. The
trenches were advanced to depths ranging from 5 to 17 feet below existing grade. The trenches were
visually logged and classified. Bulk samples and chunk samples, representative of the soils
encountered, were obtained and returned to the laboratory for testing.
During the investigation, the soils encountered were continuously examined, visually classified and
logged. Logs of the test borings and trenches are presented on Figures A-l through A-23. The logs
depict the depth and description of the various soil types encountered and include the depths which
sampling was performed.
Project No. 06301 -12-01 April 28, 1999
File No. D-4394-J01
July 17, 1989
DEPTH
IN
FEET
- 2 -
- 4 -
-
- 6 -
- 8 -
- 10 -
i "> -- iz
— ™
-
1 A _
- 18 -
- 20 -
- 22 -
- 24 -
-
- 26 -
- 28 -
SAMPLE
NO
Bl-1
Bl-2
Bl-3
Bl-4
Bl-5
Bl-6
oo
0
J_
H
LSS ''/•//_/w//,'//////,
cr
H<t
Q
3
0cra
SOIL
CLASS
(USCS)
SM
sc
SM
SM
BORING B 1
ELEVATION 255.0 DATE DRILLED 6/26/89
EQUIPMENT E100 BUCKET DRILLRIG
MATERIAL DESCRIPTION
(TOPSOIL REMOVED, APPROXIMATELY 1 1/2')
SANTIAGO FORMATION
Dense to very dense, humid, light gray,
Silty fine to coarse SANDSTONE, with
fine to medium lenses, more clayey
fine to medium more clayey, rip-up clast
„-.—-,„* iN^»J.C(^, JO ^UilliXW L ^
\ I
Very dense, slightly moist, gray,
Clavev fine to medium SANDSTONE1 3 i
Very dense, humid, light gray, Silty
fine to coarse SANDSTONE
becomes moist
iSn
S^oCL K
t
—
-
~ 8
—
-
~ 8
~ 8
-
~ 9
^7/10"
i-
H
goa •
cra
129.9
126.7
129.1
129.0
125.2
iij 'cr -3 1-HZ(/) IU
H K-o zEO
7.5
7.2
6.4
9.3
9.0
Figure A-l. Log of Test Boring B 1
SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL
S3 ... DISTURBED OR BAG SAMPLE
D... STANDARD PENETRATION TEST I... DRIVE SAMPLE (UNDISTURBED)
3 ... CHUNK SAMPLE X ... WATER TABLE OR SEEPAGE
Note: The log 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.
File No. D-4394-J01
July 17, 1989
DEPTH
IN
FEET
.. in _
- 32 -
- 34 -
. _
- 36 -
- 38 -
\ A- 40 -
- 42 -
- 44 -
"• ""
- 46 -
- 50 -
- 52 -
- 54 -
- 56 -
- 58 -
SAMPLE
NO
•n t *THI-/
Bl-8
Bl-9
Bl-10
ao
o
H
-J
^^
11
I
Ij
l|
^P
tr1U
<t
Q
3oo:
(3
v
—
SOIL
CLASS
(USCS)
SM
CL
ML
SM
CL
BORING B 1
ELEVATION 255.0 DATE DRILLED 6/26/89
EQUIPMENT El 00 BUCKET DRILLRIG
MATERIAL DESCRIPTION
., slight seepage
Very stiff, moist, yellowish brown,
Silty CLAYSTONE, lense shinv
fractures, in fine to coarse silty
sandstone
Hard, moist, yellowish brown, Sandy
SILTSTONE. with some clav
Very dense, slightly moist, light gray,
Silty fine to medium SANDSTONE, micaceous
> contact generally horizontal\ '
Very stiff, moist, brown, Silty CLAYSTONE
shiny fractures
becomes very silty, hard
zm
H 3 1L
KOJW
1U m OZUJ iIU
CL "•
-
-
~ 0a
—
—
-
—
—
_ 20
~ 16
M
%6
EQ
1 rtC -7lUj.J
120.3
122.2
IU 'IT «
(0 111H H-o z
15.0
13.7
Figure A-2^ Log of Test Boring B 1
SAMPLE SYMBOLS ... SAMPLING UNSUCCESSFUL C ... STANDARD PENETRATION TEST •-.. DRIVE SAMPLE (UNDISTURBED)
... DISTURBED OR SAG SAMPLE S ... CHUNK SAMPLE X ... UATER TABLE OR SEEPAGE
Note: The log subiurface condition* shown hereon applies only at the specific boring or trench location and
at the date indicated. It it not warranted to be representative of subsurface conditions at other locations and times.
File No. D-4394-J01
July !?•, 1989
DEPTH
IN
FEET
- OU -
- 62 -
- 64 -
SAMPLE
NO
Bl-11
>oo
o
M
i
tr.Uih-<r
Q
5ocru
SOIL
CLASS
(USCS)
CL
SM
BORING B 1
ELEVATION 255.0 DATE DRILLED 6/26/89
EQUIPMENT E100 BUCKET DRILLRIG
MATERIAL DESCRIPTION
few shiny surfaces
Very dense, slightly moist, light gray,
l Silty fine to medium SANDSTONE r
BORING 1£KMINAT£D AT 66.0 FEET
*
ig •H y h-
*£*£«iUl M O
S""o0. Z
-
20
>i-
M
2ul
Kda »
a:a
124.6
x
CE «
I-ZU) 111M 1-o zCO
10.9
^Figure A-3, Log of Test Boring B 1
SAMPLE SYMBOLS Q... SAHPLINC UNSUCCESSFUL O... STANDARD PENETRATION TEST • ... DRIVE SAMPLE (UNDISTURBED)
... DISTURBED OR BAG SAMPLE 3 ... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE
Note: The log aubiurface condition! 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.
File No. D-4394-J01
July 17, 1989
DEPTH
IN
FEET
ft _
*•
£
_ g _
ft
- 10 -
- 12 -
- 14 -
-
- 16 -
- 18 -
- 20 -
-
- 22 -
- 24 -_
- 26 -
- 28 -
SAMPLE
NO
B2-1
B2-2
B2-3
B2-4
'^/%1
Ws
#
y/S
>I'JO
O
H
H
"l>
'&
%
tt'
•
•
Vt
%ft
'/,
1
v1
Sj
•i
*ff
UJH<r
Q
*s
0a:CD
SOIL
CLASS
(USCS)
CL
i)(J
SW-SC
ML
5M-MI
ML
BORING B 2
ELEVATION 232.0 DATE DRILLED 6/26/89
EQUIPMENT E100 BUCKET DRILLRIG
MATERIAL DESCRIPTION
COLLUVIUM
Hard, moist, brown, very Sandy CLAY
^. /»«"\ Dense, humid, brown, Clayey fine to coarse
\ SAND
\
SANTIAGO FORMATION
Very dense, moist, very pale brown, slightly
Clayey fine to coarse SANDSTONE
clayey fine to medium sandy layer
N20E5SE
Clayey rip- up ciasts, becomes light
gray, micaceous
N30E10N wavy, could expect seepage
Hard, moist, yellowish brown, Sandy
SILTSTONE, with some clay, carbon
Hecks
gradational
Very dense, moist, yellow brown, Silty fine
to coarse SANDSTONE, with layers of sandy
siltstone
dipping contact
sandy siltstone
fault N50W65S fractured zone 1" wide,
slightly remolded
Hard, moist, vellow brown, Sandv
a"LJ u •H y i-
H U-
UJ H OuiJsUtL*
~ 5
~ 4
-
-
-
-
" 5
-_
-
-
10
>
H
io
V0-ITa
124.5
123.8
111.5
121.1
tx. -3 HH ZtnaiM HO Zzo
7.8
7.2
18.7
14.5
Figure A-4, Log of Test Boring B 2
SAMPLE SYMBOLS Q ... SAMPLING UNSUCCESSFUL I]... STANDARD PENETRATION TEST • ... DRIVE SAMPLE (UNDISTURBED)
... DISTURBED OR BAG SAMPLE 3... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE
Note: The log subnirface 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.
File No. D-4394-J01
July 17, 1989
«
•
P"
ta
M*
W
*»
M
«•
•
IH
•
••
IH
§•
•i
«M
Mi
W
DEPTH
» IN
, FEET
!
30
[ -
- 32 -
- 14 -
_i
- 36 -
_ •jo _jjo n
-
- 42 -
_ —
4 Ju 44 -
- 46 -
SAMPLE
MO
B2-5
B2-6
''$
WI4'','/,%w.wv//s
CDO
^-
H_i
'/y''// ''// 'r/j t'///,'fa1
'/It'/;'//'
ty',
¥/'
//''//'//'
fa,-4DUATER3
OirCJ
SOIL
CLASS
(USCS)
ML
SM
CL
CL
BORING B 2
ELEVATION 232.0 DATE DRILLED 6/26/89
EQUIPMENT E100 BUCKET DRILLRIG
MATERIAL DESCRIPTION
ML IS ION t, with some clav
fractured zone, shiny parting surfaces
approximately 4 " wide, roughly horizontal
., Very dense moist light gray Silty r
' fine to coarse SANDSTONE '
Hard, moist, pale olive, Silty CLAYSTONE
with some sand, few shiny surfaces
Hard, moist, brown. Siltv CLAYSTONE.
shiny fracture surfaces
BORING TERMINATED AT 47.0 FEET [RATIONSTANCEJS/FT.EmO
SmoQ.
-
—
-
10
_
-
~ 9 )ENSITYC.F.K1
Q
121.0
110.1
X01Isin tilH 1-o zr o
14.6
19.4
'Figure A-5, Log of Test Boring B 2
SAMPLE SYMBOLS Q ... SAMPLING UNSUCCESSFUL D ... STANDARD PENETRATION TEST • ... DRIVE SAMPLE (UNDISTURBED)
... DISTURBED OR BAG SAMPLE 3 ... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE
Note: The log 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 tunes.
File No. D-4394-J01
July 17, 1989
DEPTH
IN
FEET
- 2 -
"
- 4 -
-
- 6 -
- 8 -
- 10 -
-
- 12 -
~ •"
- 14 -
-
- 16 -
-
- 18 -
- 20 -
™ ™
- 22 -
• ~
- 24 -
-
- 26 -
"
- 28 -
"" •"
SAMPLE
NO
B3-1
B3-2
B3-3
B3-4
B3-5
B3-6
aa
o
H
j%4$%
W%Svys$/s
Ws/ss;y////A
W//AWXM
'
,
,
•
"
w$
Vy/%/
VwW
vflyy/wW/
«
trin
<t
a
0Ka
SOILcuss
(USCS)
CL
CL
SC
SM
CL
BORING B 3
ELEVATION 215.0 DATE DRILLED 6/27/89
EQUIPMENT E100 BUCKET DRILLRIG
MATERIAL DESCRIPTION
FILL
•^ Loose damp sray Sandy CLAY /-
\ /
COLLUVIUM
Hard, slightly moist, Sandy CLAY.
porous ^A r
SANTIAGO FORMATION
Dense to very dense, humid, light yellow
brown, slightly Clayey fine to coarse
SANDSTONE, with clasts of brown
claystone, weathered sandstone
claystone lense
siltstone lense
Very dense, slightly moist, light gray,
slightly Silty fine to coarse SANDSTONE
clayey lense
becomes moist
medium to coarse
few ciaystone lenses
becomes very pale yellow brown with
pebbles
contact: N35E5W
Very stiff, moist, brown, Sandy
CLAYSTONE
slightly weathered with contact, could
be areas of seepage in future, non-
continuous shiny parting surfaces, some
dipping out of slope
is*;h- 5 U.
afc w
iu y o
III — 1Ui Jv EQ
-
" 4
•"•
—
5
-
-
~
-
" 5
-
-_
~ 7
~
—
-
~ 5
-
KHSulZ ""go
1°"
122.9
127.2
126.3
127.1
113.4
IU '9r .^
in in
H t-o zZ 0u
7.2
8.8
9.8
10.1
17.3
Figure A-6, Log of Test Boring B 3
Q... SAMPLING UNSUCCESSFUL C ... STANDARD PENETRATION TEST • ... DRIVE SAMPLE (UNDISTURBED)
13 ... DISTURBED OR BAG SAMPLE S ... CHUNK SAMPLE Z ... WATER TABLE OR SEEPAGE
Note: The log aubturface condition! 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.
File No. D-4394-J01
July 17, 1989
*
•J*
ftv
«""
Is*
„
mm
to*
••
m,
**
*.
"*
-•H
BW
ft*
tj»
•»
Iff
toj
DEPTH
IN
FEET
- 32 -
- 34 -
- 36 -
- 38 -
- 40 -
- 42 -
-
- 44 -
- 46 -
- 48 -
- 50 -
- 52 -
- 54 -
- 56 -
- 58 -
SAMPLE
un
B3-7
B3-8
B3-9
B3-10
B3-11
o0
o
H-1
22%$'//////Wti
mkW//
'</M
'''<w.''','%
'''VWw.w'W/\
?//////
ai
<r
a
otxu
SOIL
CLASS
(USCS)
CL
SM
CL
BORING B 3
ELEVATION 215.0 DATE DRILLED 6/27/89
EQUIPMENT E100 BUCKET DRILLRIG
MATERIAL DESCRIPTION
weathered zone
Very dense, slightly moist, pale yellowish
brown, Silty fine to medium SANDSTONE, with
some clay and coarse grains
becomes pale yellowish brown mottled with
blue
Very stiff to hard, moist, brown, Silty
CLAYSTONE, few shiny surfaces
weathered, fractured
shiny parting surfaces, few fractures
filled with gypsum
fracture N5W20W
becomes brown, occasional mottled
with green
becomes very sandy, mottled with gray
blue in places
°s •
*~ § "•£«?<"
UJtfjOS^m0.
7
—
_
—
—
" 8
-
-
~ 13
So" •
V.a
116.3
118.8
106.6
ui "<r «
(0 UlH »-O Zso
15.5
15.6
20.8
"•Figure A-7, Log of Test Boring B 3
SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL C ... STANDARD PENETRATION TEST • ... DRIVE SAMPLE (UNDISTURBED)
... DISTURBED OR BAG SAMPLE 3 ... CHUNK SAMPLE 3C ... WATER TABLE OR SEEPAGE
Note: The log subsurface conditions ihown 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.
File No. D-4394-J01
July 17, 1989
DEPTH
IN
FEET
- 64 -
- 66 -
- 68 -
SAMPLE
NO.
ao
0
jz
H
J
B
crtu
<r
a
^oa.o
SOIL
CLASS
(USCS5
SC
SM
BORING B 3
ELEVATION 215.0 DATE DRILLED 6/27/89
EQUIPMENT E100 BUCKET DRILLRIG
MATERIAL DESCRIPTION
Very dense, moist, yellowish brown
mottled with gray blue, Clayey fine
to medium SANDSTONE, with some silt,
\ siltstone lense '
Very dense, humid, pale gray, Silty
fine to coarse SANDSTONE
BORING TERMINATED AT 70.0 FEET
ZjiU
H £J K
tr £ m
k<n°iiiHI Ji" £Q
0. *
-
_
-
-
-
—
1-H
zul
Q«^ •
cca
118.7
123.0
XuCK -.
m \aH H-o zr o
14.7
11.2
**Figure A-8, Log of Test Boring B
SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL
... DISTURBED OR BAG SAMPLE
D... STANDARD PENETRATION TEST
S ... CHUNK SAMPLE
DRIVE SAMPLE (UNDISTURBED)
... WATER TABLE OR SEEPAGE
Not*: The log 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.
File No. D-4394-J01
July 17, 1989
DEPTH
IN
FEET
^
- 4 -
- 6 -
-
8 _~
- 10 -
- 12 -
- 14 -
i
- 16 -
-
- 18 -
-
?nzu
AM
- 24 -
- 26 -
- 28 -
SAMPLE
NO
B4-1
B4-2
B4-3
B4-4
B4-5
aa
o
KH
-1
'//Ays////
'^%,\vX\\\N\XXVWWvXm^^¥/////,
&//A
W//S•
C£HI
<I
a
•^ocru
SOIL
CLASS
(USCS)
CL
CL
CL-SC
SC
SM
BORING B 4
ELEVATION 229.0 DATE DRILLED 6/27/89
EQUIPMENT E100 BUCKET DRILLRIG
MATERIAL DESCRIPTION
TOPSOBL
Hard, slightly moist, gray, Sandy
_ f^T A ~v nrtTViiic *-T \^L,f\ i . porous r
SANllAtkj FORMATION
Stiff, moist, yellow brown, Silty
CLAYSTONE. weathered
Very dense, humid, pale yellowish brown,
Siltv fine to coarse SANDSTONE with some
clay
could have seepage with increased
i irrigation, Contact N15E10N '\ '
Very stiff, moist, yellowish brown, very
', sandy fine to coarse CLAYSTONE. weathered ;
i shining parting surfaces ', i
Very dense, slightly moist, yellowish
brown, Clayey fine to coarse SANDSTONE
Very dense, moist, very pale yellowish
brown, Silty fine to coarse SANDSTONE
with some clay
ig^
!>••«
i"SouS^gj
0. "•
~ 5
-
»
" 6
-
~ 5
7
i-H
gt
go
>•<*•anQ
128.3
123.6
118.6
130.3
01 '
01 UJM t-o zro
8.8
6.7
5.8
8.1
to Figure A-9,, Log of Test Boring B 4
SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL B ... STANDARD PENETRATION TEST
^ ... DISTURBED OR BAG SAMPLE S ... CHUNK SAMPLE
1 DRIVE SAMPLE (UNDISTURBED)
;... WATER TABLE OR SEEPAGE
.„, Note: The log aubiurface condition* thown hereon applies only at the specific boring or trench location and
at the date indicated. It it not warranted to be representative of subsurface condition* at other location! and time*.
File No. D-4394-J01
'July 17, 1989
m
•»
m
~
to
n*
*•»
ts»
<*»
«•*
P*
«
«*.
••t
••>
„ ,
*•
**•
I
••
^
J
1
IV
DEPTH
IN
FEET
_ in _
- 32 -
- 34 -
-
- 36 -_
19 _
- 40 -
- 42 -
- -<
- 44 -
-
- 46 -
A O
SAMPLE
NO
B4-6 1
B4-7 I
1r
1
B4-S 1
j
a0
^
H
-1
v
.V
I V-:
K ^yyy
^^^
^^B
^flti
^^»y:;i1
aUJ
<r
->o
(Xu
x
SOIL
CLASS
(USCS)
SM
CL
CL
SM
BORING B 4
ELEVATION 229.0 DATE DRILLED 6/27/89
EQUIPMENT E100 BUCKET DRILLRIG
MATERIAL DESCRIPTION
seepage
Very stiff, moist, gray-brown, Silty
CLAYSTONE fractured with shiny
surfaces, discontinuous joint surfaces
Very stiff to hard, moist, yellowish
brown, Sandy CLAYSTONE
becomes very sandy
Very dense, moist, light gray, Silty fine to
medium SANDSTONE, micaceous
BORING TERMINATED AT 50.0 FEET
.
2qn
&&
UJ H O
ul^mQ. a
8
-
-
-
-
~ 1
-
-
-
-
-
~ 14
V
|d
ITQ
126.3
Ul 'cr -
H Zm tu
H 1-o zr o
9.0
••Figure A-10, Log of Test Boring B 4
SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL B ... STANDARD PENETRATION TEST
^ ... DISTURBED OR BAG SAMPLE 3 ... CHUNK SAMPLE
DRIVE. SAMPLE (UNDISTURBED)
... WATER TABLE OR SEEPAGE
Note: The log 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.
File No. D-4394-J01
July 17, 1989
DEPTH
IN
FEET
- 0 -
- 2 -
~
- 4 -
SAMPLE
NO.
Tl-1 \
a
THOLOH
%%l
llili
'7%'
4/%'>
'.y/fy.',
IT1U
UNOUAOo:a
SOIL
CLASS
(USCS)
SM
ML
TRENCH T 1
ELEVATION 142.0 DATE DRILLED 6/23/89
EQUIPMENT 555JD BACKHOE
MATERIAL DESCRIPTION
FILL
Dense, humid, gray, Silty fine to coarse f
SAND
i>AJN 11AGO FORMATION
Hard, slightly moist, pale brown, Clayey
SILTSTONE. with some fine sand, jointed
TRENCH TERMINATED AT 5.0 FEET
(DIFFICULT DIGGING)
ig •M y K-i-5u.<t E \£<"£^™ .. _A
ujSo
Q. K
«
KM
&.
ira
129.4
syx
SKHZin 111M t-ii
10.1
*• Figure A-ll, Log of Test Trench T 1
SAMPLE SYMBOLS 0 ... SAMPLING UNSUCCESSFUL I] ... STANDARD PENETRATION TEST • DRIVE SAMPLE (UNDISTURBED)
... DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE JL... WATER TABLE OR SEEPAGE
Note: The log subsurface conditions shown hereon applies only at the specific boring or trench location and
at the date indicated. It it not warranted to be representative of subsurface condition* at other locations and times.
,File No. D-4394-J01
'July 17, 1989
DEPTH
IN
FEET
0
_
- 2 -
* *~
- 4 -
SAMPLE
MO
T2-1 :
',
><30
o)_
H-1
" _ . •
crIUi—<r
a
3
OK(3
SOIL
CLASS
(USCS)
SM
SM
TRENCH T 2
ELEVATION 259.0 DATE DRILLED 6/23/89
EQUIPMENT 555JD BACKHOE
MATERIAL DESCRIPTION
COLLUVIUM
Dense, slightly moist, pale grayish-brown
Silty fine to coarse SAND, with little
clay, trace pebbles
SANTIAGO FORMATION
Very dense, humid, pale brown, Silty fine
I becomes very pale brown
TRENCH TERMINATED AT 5.0 F£ET
(DIFFICULT DIGGING)
•
§UJ .
I|S
111 w O
Cu^m
Q. *
~
—
H
M
•
(XQ
124 1
tr «
(0 UJM h-O Zzo
6 1
•Figure A-12, Lo^ of Test Trench T 2
SAMPLE SYMBOLS [... SAMPLING UNSUCCESSFUL E ... STANDARD PENETRATION TEST I... DRIVE SAMPLE (UNDISTURBED)
[... DISTURBED OR BAG SAMPLE 3 ... CHUNK SAMPLE Z ... WATER TABLE OR SEEPAGE
Not*: The log subturface 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.
File No. D-4394-J01
July 17, 1989
DEPTH
IN
FEET
"
- 2 -
A- 4 -
-
- 6 -
- 8 -
_ i r\
- 12 -
SAMPLE
NO
T3-1 I
T3-2 I
I
T3-3 !
T3-4 j
>oo
o
H
1
r'
i''
I
^?
o:UJH-<r
Q
3
0aC3
SOIL
CLASS
(USCS)
SM
SM
ML
TRENCH T 3
ELEVATION 208.0 DATE DRILLED 6/23/89
EQUIPMENT 555JD BACKHOE
MATERIAL DESCRIPTION
FILL
Dense, humid, pale brown, Silty fine to
coarse SAND
ALLUVIUM
Very dense, slightly moist, gray, Silty
fine to medium SAND, some clay
SANTIAGO FORMATION
Hard, moist, yellow brown, Clayey
SILTSTONE, verv few fine sand grains
TRENCH TERMINATED AT 13.0 FEET
(DIFFICULT DIGGING)
§UJ .
a S OT
UJ W O
m^oQ.
*~
-
—
-
-
1-
IS
crQ
113.7
1060
en -
in ujH t-o zr o
8.7
15.1
Figure A-13, Log of Test Trench T 3
SAMPLE SYMBOLS Q... SAHPLING UNSUCCESSFUL C... STANDARD PENETRATION TEST I... DRIVE SAMPLE (UNDISTURBED)
... DISTURBED OR BAG SAMPLE S ... CHUNK SAMPLE f ... WATER TABLE OR SEEPAGE
Note: The log 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.
File No. D-4394-J01
July 17, 1989
«"
«.
m
PM
M
fSI
m
•"
*•
|-
(Hi
^
«•
SB
Ml
m
m
DEPTH
IN
FEET
n _
- 2 -_
- 4 -
- 6 -
-
8
_
- 1 n _1U
SAMPLE
HO
a0
o
H_i
•''////',Zi&i
a.UJ
<t
a
oa:u
SOIL
CLASS
(USCS)
SM
SM
ML
TRENCH T 4
ELEVATION 218.0 DATE DRILLED 6/23/89
EQUIPMENT 555JD BACKHOE
MATERIAL DESCRIPTION
ALLUVIUM/COLLUVIUM
Dense to very dense, humid, pale brown,
Silty fine to coarse SAND
few cobbles
carbon flecks
Very dense, humid to slightly moist, light
gray, Silty fine to coarse SAND.
cohesioniess lenses
SANTIAGO FORMATION
Hard, slightly moist, pale olive, Clayey
SILTSTONE with slight fine sand, jointed
TRENCH TERMINATED AT 11.0 FEET
(DIFFICULT DIGGING)
5g •M ti 1-
t-I"-<r 2 \
H^S
z«35^a. "
-_
-
—
>i-M
^So>.*•V.a
xUJIT «3 H1- Zin luH Ho zso
'Figure A-14, Log of Test Trench T 4
r T- 0^™™ oSAMPLE SYMBOLS ... SAMPLING UNSUCCESSFUL C ... STANDARD PENETRATION TEST_
... DISTURBED OR BAG SAMPLE H ... CHUNK SAMPLE
... DRIVE SAMPLE (UNDISTURBED)
... WATER TABLE OR SEEPAGE
Note: The lag 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.
File No. D-4394-J01
July 17, 1989
DEPTH
IN
FEET
0
_
- 2 -
4
_
-
-6-1
8 _j
• -
- 10 -
- 12 -
SAMPLE
un
15-1 \
T5-2 I
£
T5-3 I
>CD0
0
K
Hf
^VM
'$/$/
uii-<r
^0IT(3
SOILcuss
(USCS)
SM
SM
SC
ML
TRENCH T 5
ELEVATION 205.0 DATE DRILLED 6/23/89
EQUIPMENT 555JD BACKHOE
MATERIAL DESCRIPTION
ALLUVIUM
Dense, humid, dark brown-gray, Silty
medium to coarse SAND, slightly
porous
becomes brown, less porous
Dense, slightly moist, pale brown,
> Silty fine to coarse SAND, slightly ,'
' clayey <i
Dense, moist, brown, Clayey fine to
coarse SAND
SANTIAGO FORMATION
Hard, moist, brown. Sandy SILTSTONE
jointed
TRENCH TERMINATED AT 13.0 FEET
(DIFFICULT DIGGING)
§m .
iij-Sj
UJ In O
Jn ^J m
Q. *
-
-
—
-
-
-
H
H
.
tra
105.8
106.0
cc »
HZ(/) UJ
H 1-o zs o
4.2
13 1
Figure A-15, Log of Test Trench T 5
SAMPLE SYMBOLS Q... SAMPLING UMSUCCESSRIL B ... STANDARD PENETRATION TEST
... DISTURBED OR BAG SAMPLE CHUNK SAMPLE
... DRIVE SAMPLE (UNDISTURBED)
'... WATER TABLE OR SEEPAGE
Note: The log 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.
File No. D-4394-J01
July 17, 1989
DEPTH
IN
FEET
- 2 -
"
_ A —
-
- 6 -
- 8 -
- 10 -
- 12 -
-
- 14 -
- 16 -
SAMPLE
NO
T6-1 f:
>oo
o
H-1
'%%%
%%W%
Y/S/fi'
crUIH
§Q
0IT<3
SOIL
CUSS
(USCS)
SM
CL
SM
ML
TRENCH T 6
ELEVATION 195.0 DATE DRILLED 6/23/89
EQUIPMENT 555JD BACKHOE
MATERIAL DESCRIPTION
ALLUVIUM
> Dense, humid, brown, Silty fine to ,'
' coarse SAND with humus i
Hard, slightfy moist, dark'gfay brown",
very Sandy CLAY, slightly porous
v /
Dense, slightly moist to moist, pale
brown, Silty fine to coarse SAND.
mottled appearance
SANTIAGO FORMATION
Stiff, very moist, pale brown, Sandy
SILTSTONE"A /
TRENCH TERMINATED AT 17.0 FEET
§IU .
i- 5 a.<t 2 \a ai m
w
UJ m
0. "•
^
-
-
-
-
>
H1"!<
Ka
100.8
tr »3 HK ZUl UJ1-4 H
r o
11.6
Figure A-16, Log of Test Trench T 6
SAMPLE SYMBOLS Q ... SAMPLING UNSUCCESSFUL
... DISTURBED OR BAG SAMPLE
E... STANDARD PENETRATION TEST
S ... CHUNK SAMPLE
DRIVE SAMPLE (UNDISTURBED)
:... WATER TABLE OR SEEPAGE
Not*: Tha log aubiurfaee condition* «hown hereon applies only at the specific boring or trench location and
at the date indicated. It is not warranted to be representative of subsurface condition! at other locations and times.
File No. D-4394-J01
July 17, 1989
DEPTH
IN
FEET
- 2 -
-
- A -
-
- 8 -
t n —
SAMPLE
un
T7-1 i
i
>CJO
H
'%%&
w$
wv%v,
CE111H<t
Q
OITCJ
SOIL
CLASS
(USCS)
sc
CL
SM
TRENCH T 7
ELEVATION 195.0 DATE DRILLED 6/23/89
EQUIPMENT 555JD BACKHOE
MATERIAL DESCRIPTION
COLLUVIUM
Dense, humid, black, slightly Clayey
fine to coarse SAND
i, becomes more clayey r
SANTIAGO FORMATION
Very stiff, moist, tan mottled with
black, Sandy CLAY, with trace pebbles
contact wavy
Very dense, slightly moist, very palebrown, Silty fine to medium SAND.
micaceous
TRENCH TERMINATED AT 10.0 FEET
(DIFFICULT DIGGING)
§U .
!Ǥin ~^m sj JQ
Q. ^
—
-
-
™
HM
|d•
ITa
102.5
a: -
H Zifi tuM 1-o zro
16.4
*"• Figure A-17, Log^ of Test Trench T 7
SAMPLE SYMBOLS 0... SAMPLING UNSUCCESSFUL C ... STANDARD PENETRATION TEST V... DRIVE SAMPLE (UNDISTURBED)
... DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE ... WATER TABLE OR SEEPAGE
Note: The log subsurface condition* shown hereon applie* 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.
File No. D-4394-J01
July 17, 1989
DEPTH
IN
FEET
- 2 -
- 4 -_ _
- 6 -
— —
- 8 -
SAMPLE
NO
2^
>_
13O
0
l-l
^
tr1U
<t
a
0tro
SOIL
CLASS
(USCS)
CL
ML
SM
TRENCH T 8
ELEVATION 196.0 DATE DRILLED 6/23/89
EQUIPMENT 555JD BACKHOE
MATERIAL DESCRIPTION
COL.LUY1UM
"\ Hard, humid, dark gray, Sandy CLAY f
SANTIAGO FORMATION
Hard, moist, brown, Sandy SILTSTONE.
jointed
becomes more clayey
1/16" thick, apparently discontinuous
i bedding plane shear, NICE dipping 65 (1 degrees W '
contact gradational
"I Very dense, slightly moist, light gray, r
\ Silty fine to medium SANDSTONE, micaceous 1
TRENCH TERMINATED AT 9.5 FEET
(DIFFICULT DIGGING)
^ tu
t—% \L
afc w
m OT °
i
-
-
-
-
-
-
—
^-
M
|o
>-a-tra
x
IX «
H Zin tuH H
co
Figure A-18, Log of Test Trench T 8
SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL C... STANDARD PENETRATION TEST
ffl ... DISTURBED OR BAG SAMPLE S ... CHUNK SAMPLE
... DRIVE SAMPLE (UNDISTURBED)
... WATER TABLE OR SEEPAGE
Note: The log 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.
File No. D-4394-J01
July 17, 1989
DEPTH
IN
FEET
2
_
- 4 -
-
- 6 -
-
- 8 -
-
- 10 -
-
- 12 -
""' """
- 14 -
i /;
SAMPLE
NO
T9-1 Ia
ao
o
H
H
mwft"/S/sf/
in^nf
W//S
ITUJ
3
^O(TO
SOIL
CLASS
(USCS)
SC
SM
SC
SC
ML
TRENCH T 9
ELEVATION 182.0 DATE DRILLED 6/23/89
EQUIPMENT 555JD BACKHOE
MATERIAL DESCRIPTION
COLLUVIUM
Dense, humid, dark gray, slightly Clayey
f MA f>* **£k J* W* ^ A MT^ l«.JiX J<^llll"i i me lu uicuiuui o/AiNL/, puiuiu> r\ /
ALLUVIUM
Very dense, humid, very pale brown,
Silty fine to coarse SAND, mottled.
roots, layers of humic material
becomes less mottled, few lenses of
fine to medium sand
carbon flecks
Very dense, moist, brown, Clayey fine
~\ to coarse SAND, mottled with roots f
SANTIAGO FORMATION
Very dense, moist, pale brown, Clayev
fine to coarse SANDSTONE
Hard, moist, pale brown, Sandy SJLTSTONE
TRENCH TERMINATED AT 16.0 FEET
(DIFFICULT DIGGING)
og •M y H
IIS
UJ % Q
U -J
Q. tt
-
-
-
-
—
HM
Z f
" .
^_ ^
Xa
101.8
01 *
H Z(0 UlH (-O Zso
6.3
Figure A-19, Log of Test Trench T 9
SAMPLE SYMBOLS Q... SAMPLING UNSUCCESSFUL B ... STANDARD PENETRATION TEST
H ... DISTURBED OR BAG SAMPLE & ... CHUNK SAMPLE
... DRIVE SAMPLE (UNDISTURBED)
... WATER TABLE OR SEEPAGE
Note: Th« log aubturface conditions shown heraon 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.
File No. D-4394-J01
July 17, 1989
DEPTH
IN
FEET
- 2 -
- 4 -
- 6 -
- 8 -
- 10 -
_ i "> —
-
SAMPLE
NO.
T10-1 ;
t
m
LITHOLOIX
zs/%/
YfflM
wfa
K ^s. yv ^fS. ft /
' Vx 'X '
:x ^/
|P
;||^
y/y////
wy//y
ITUJ
QROUNDUASOIL
CLASS
(USCS)
SM
CL
ML
SC
TRENCH T 10
ELEVATION 164.0 DATE DRILLED 6/23/89
EQUIPMENT 555JD BACKHOE
MATERIAL DESCRIPTION
FILL
-« Loose damp light gray slightly Silty r-
\ . fine to coarse SAND f
REWORKED ALLUVIUM
Very stiff, moist, dark gray, Sandy
CLAY
-y P^e j-
ALLUVIUM
Very stiff, moist, pale brown, very
Clayey SILT
SANTIAGO FORMATION
Very dense, moist, blue-gray and pale
brown, Clayey fine to coarse SANDSTONE,
with roots
TRENCH TERMINATED AT 14.0 FEET
(DIFFICULT DIGGING)
Sg •PENETRATJRESISTANBLOUS/Fl"*
-
—
—
-
£
i1
101.6
MUJ
MOISTURCONTENT,17.7
Figure A-20, Log of Test Trench T 10
SAMPLE SYMBOLS O... SAMPLING UNSUCCESSFUL I] ... STANDARD PENETRATION TEST I... DRIVE SAMPLE (UNDISTURBED)
i ... DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE X... WATER TABLE OR SEEPAGE
Note: The log subiurface 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.
File No. D-4394-J01
July 17, 1989
DEPTH
IN
FEET
n
- 2 -
A _
_
- ftO ~"
- 8 -
- 10 -
- 12 -
M
_
SAMPLE
Ufl 0
H
-1
%%%.fss/yy/
vww
7%//W,
'$$&
vW/frYMyfa
yffi&s
<ffiw4ffi/faw%,
m
B
IT1U
<t
Q
O
U
SOIL
CUSS
CUSCS)
CL
CL
SC
SM
TRENCH T 11
ELEVATION 232.0 DATE DRILLED 6/26/89
EQUIPMENT 555JD BACKHOE
MATERIAL DESCRIPTION
ML1.
Hard, slightly moist, gray, Sandy CLAY, ;
i porous i\ '
"i Very stiff, moist, brown. Sandy CLAY, r
I faint odor /
\ 1
SANTIAGO FORMATION
Dense, moist, gray mottled with orange
Clayey fine to coarse SANDSTONE
becomes gray, very dense
becomes dark gray, moist
Very dense, slightly moist, light gray,
Silty fine to coarse SANDSTONE
TRENCH TERMINATED AT 14.0 FEET
(DIFFICULT DIGGING)
§g(.
52 Na E «>
ui jj, o
111 K Qa.
—
-
-
-
H
S"7
" •
tra
UJ 'cr -
<n uiH Ko z£ O
Rgure A-21, Log^ of Test Trench T 11
SAMPLE SYMBOLS O... SAMPLING UNSUCCESSFUL D... STANDARD PENETRATION TEST •.... DRIVE SAMPLE (UNDISTURBED)
DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE 3T... WATER TABLE OR SEEPAGE
Note: The log subiurface condition! ihown hereon applies only at the specific boring or trench location and
at the date indicated. It is not warranted to be representative of subiurface conditions at other locations and times.
File No. D-4394-J01
July 17, 1989
DEPTH
IN
FEET
- o -
1
- 4 -
- 6 -
- 8 -
1 A- 10 -
- 12 -
SAMPLE
un
CJ0
a
HHt-i
9
!&Wyy,
m9/
aUJ
<t
->oa:a
SOIL
CLASS
(USCS)
CL
SM
SC
TRENCH T 12
ELEVATION 223.0 DATE DRILLED 6/26/89
EQUIPMENT 555JD BACKHOE
MATERIAL DESCRIPTION
COLLUVIUM
Hard, moist, dark brown, very Sandy
T v^ivA i . porous r
SAM IlAC-kJ J-ORMATION
Very dense, humid, very pale brown,
Siltv fine to coarse SANDSTONE
Very dense, slightly moist, yellowish brown,
Clavev fine to coarse SANDSTONE
TRENCH TERMINATED AT 13.0 FEET
0* •U t"\ 'WU t^
•- tf 1.<t £ \£">i
HI In Ozgj _jiu Kma. K
-
-
-
>H
2ol
SoQ .
V0-
X01
SBO UJH K
ro
Figure A-22, Log of Test Trench T12
SAMPLE SYMBOLS D... SAMPLING" UNSUCCESSFUL E... STANDARD PENETRATION TEST" • ... DRIVE SAMPLE (UNDISTURBED)
':... DISTURBED OR- BAG SAMPLE ... CHUNK SAMPLE I... WATER TABLE OR SEEPAGE
Note: The log subsurface condition* shown hereon applies only at the specific boring or trench location and
at the date indicated. It is not warranted to b« representative of subsurface conditions at other locations and times.
File No. D-4394-J01
July 17, 1989
DEPTH
IN
FEET
- 2 -
- 4 -
- 6 -
- 8 -
•* —
- 10 -
- — i
- 12 -
SAMPLE
NO.
T13-1 j
o0
o
H
H_1
HI
^J^
1
9W%fo
tr01
UNDUAOIT13
SOIL
CLASS
(USCS)
CL
5M-MI
SC
SM
TRENCH T13
ELEVATION 206.0 DATE DRILLED 6/26/89
EQUIPMENT 555JD BACKHOE
MATERIAL DESCRIPTION
COLLUVIUM
Hard slightly moist dark brown very r\ Sandy CLAY, porous /
SAJNllAGO FORMATION
Very stiff, moist, pale brown and brown
layers of Sandv SILTSTONE and very
Silty fine to medium SANDSTONE
Very dense, slightly moist to moist,
pale gray and brown, Clayey fine to
coarse SANDSTONE with carbon1 /\ ,
Very dense, slightly moist, pale brown,
Silty fine to coarse SANDSTONE
becomes cobbly
TRENCH. TERMINATED AT 12.0 FEET
(DIFFICULT DIGGING)
5g .H y. H
Sr^
*23UJ m O
Zm"iugm0. tt
-
-
-
™"
~"
-
—
>
H
2ulgo
>°^XQ
106.9
X111tz -tt(n ui
H 1-o zso
14.7
Figure A-23, Log: of Test Trencir T13
SAMPLE SYMBOLS Q... SAMPLING UNSUCCESSFUL C... STANDARD PENETRATION TEST •"... DRIVE SAMPLE (UNDISTURBED)
! ... DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE 3C... WATER TABLE OR SEEPAGE
Not*: Tb« log subsurface condition* shown hereon applies only at the specific boring or trench location and
at the date indicated. It ii not warranted to be representative of subsurface conditions at other locations and times.
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APPENDIX
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 relatively
undisturbed samples were tested for their in-place dry density, moisture content, shear strength, and
expansion potential.
The maximum dry density and optimum moisture content of selected bulk samples were determined
in accordance with ASTM Test Procedure D1557-78, A. Portions of the bulk samples were then
remolded to selected densities and subjected to direct shear tests and expansion tests. Direct shear
tests, and expansion tests were also performed on relatively undisturbed samples.
The results of our laboratory tests are presented in tabular form herein. The in-place density and
moisture characteristics are also presented on the logs of the test borings and trenches.
TABLE B-l
SUMMARY OF LABORATORY MAXIMUM DRY DENSITY
AND OPTIMUM MOISTURE CONTENT TEST RESULTS
ASTM D 1557
Sample
No.
Bl-6
Bl-10
Description
Light gray, Silty, fine to coarse SANDSTONE
Brown, Silty CLAYSTONE
Maximum Dry
Density (pcf)
10.0
17.2
Optimum Moisture
Content (% dry wt.)
127.3
113.5
TABLE B-ll
SUMMARY OF DIRECT SHEAR TEST RESULTS
Sample No.
Bl-5
Bl-6*
Bl-7
Bl-10*
B3-10
Dry Density
(pcf)
122.4
114.5
105.3
102.9
101.9
Moisture Content
(%)
11.5
10.0
20.2
16.2
21.7
Unit Cohesion
(psf)
460
350
500
630
440
Angle of Shear
Resistance (degrees)
42
33
27
22
29
*Sample remolded to approximately 90 percent relative density at near optimum moisture content.
Project No. 06301-12-01 -B-l -April 28, 1999
TABLE B-lll
SUMMARY OF LABORATORY EXPANSION INDEX TEST RESULTS
Sample
No.
Bl-10
Moisture Content
Before Test (%)
11.3
After Test (%)
27.3
Dry
Density (pcf)
105
Expansion
Index
93
Project No. 06301-12-01 -B-2-April 28, 1999
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APPENDIX C
RECOMMENDED GRADING SPECIFICATIONS
for
SPYGLASS
CARLSBAD, CALIFORNIA
PROJECT NO. 06301-12-01
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 (horizontal:vertical), 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 -
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. Soil 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 D1196-64, 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
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