HomeMy WebLinkAbout; La Costa Valley Unit 5 Lots 229-232; Soils Report; 1981-02-20a
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GEOTECHNICAL INVESTIGATION
PROPOSED CONDOMINIUM.DEVELOPMENT
LA COSTA VALLEY UNIT.NO. 5,
LOTS 229 THROUGH 232
ALICANTE ROAD AND ALTISMA WAY
CARLSBAD, CALIFORNIA
February 20, 1981
Project No. 4800670-02
ENGINEERING DEPT. LIBRARY
City of Cartsbad
2075 Las Palmas fhih Carlsbad CA 92009-4859
Prepared for
Caringa Investment Co.
1224 Prospect Street
La Jolla, California 92037
4393 VIEWRIDGE AVENUE, SUITE 4 SAN DIEM CALIFORNIA 92123 (619) 292-8030. (800) 447-2626
FAX (619) 292-0771
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LEIGHTON AND ASSOCIATES
Geotedmicd ond Environmenid Engiiering Consuhnts
February 20. 1981
Project No. 4800670-02
‘.
TO: Caringa Investment Co.
1224 Prospect Street
La Jolla, California 92037
SUBJECT: Geotechnical Investigation
Proposed Condominium Development
La Costa Valley Unit No. 5, Lots 229 through 232
Alicante Road-and-Altisma Way
Carlsbad-, California ( /
Gentlemen:
In accordance with your request, we have performed a geotechnicalinvestiga-
tion of the subject property. The purpose of the investigation was to determine
the suitability of the geologic and soil conditions at the site in relation to
the planned condominium development.
Our investigation consisted of the following:
Review of published and unpublished geologic information relevant to the
site and previous geotechnical reports for the site by Benton Engineering,
Inc.
Geologic'mapping of the site.
Subsurface investigation consisting of logging and sampling of nine large diameter test borings.
Laboratory testing of samples collected during the subsurface investigation.
Engineering and geologic analysis.
Preparation of this report.
4393 VIEWRID@ AVENUE, SUITE Q SAN DIEGQ CALIFORNIA 92123 (619) 292-8030 l (800) 447-2626
FAX (619) 292-0771
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4800670-02
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1 Geologic mapping was accomplished on a 20-scale topographic map of "La Costa
'Condominiums" by Pountney & Young, Inc. The topographic base fork the Geo-
.- I technical Map, Plate 1, is a 20-scale "Grading Plan for La Costa Condominiums" ~. 1 prepared by Pountney & Young, Inc., dated January, 1981.
a: The subject site was graded between May and October 1970 under the supervision
of Benton Engineering,, Inc. following a "Preliminary Soils Investigation, La
Costa Valley Unit NO--~" prepared by the same firm and dated January 16,~49TO. A compaction report entitled "Final Report on Compacted Filled Ground, Lots
229 to 242, inclusive, Lots 244 to 250, inclusive, and Certain Street Areas,
La Costa Valley Unit No. 5" was issued November 4, 1970 by Benton Engineering, Inci upon completion of grading.~
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Accompanying Illustrations and Appendices
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l Figure 1 - Index Map
a Plate 1 - Geotechnical Map and Cross-Sections
l Appendix A - Boring Logs 8-Ithrough B-9
- l Appendix B - Results of Laboratory Testing
l Appendix C - Generalized Earthwork and Grading Specifications. ., .~ " I - I Site Description
The irregular-shaped site, encompassing approximately 5 acres is located'on -
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the north side of San Marcos Creek Valley (I
is bounded on the north by Caringa Way, on the east by Altisma Way, on the south
by Alicante Road, and on the west by existing development. The property con-
see Index Map,' Figure 1). The site
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sists of four, roughly equally-sized, graded lots.
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Prior to grading the site was situated on a moderately sloping hillside adjacent
to a south-flowing tributary of San Marcos Creek. Grading terraced the ~hillside
and filled portions of the drainage course. At present the site consists of a
relatively flat terrace bounded on the south by a 30 to 40-foot high 1.5 to 1
cut and fill slope.
The eastern and southeastern slopes (primarily fill) are severely eroded with nu-
merous gullies to 10 feet in depth. Erosion of the terrace edge. is characterized
by gully heads and piping.
4 1~ '~ Surface drainage on the eastern half of the site (Lots 229 and 230) is to the
east over the existing cut slope and to the south through a concrete "down .~~
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drain" to Alicante Road. The western portion of the site drains to a storm
drain fin the southwestern corner of the site. .a - ,1
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FIGURE I
GEOTECHNICAL INVESTIGATION
PROPOSED CONDOMINIUMS LA COSTA VALLEY UNIT NO. 5, LOTS 229 THROUGH 232
CARLSBAD, CALIFORNIA
Basis: U.S.G.S. Encinitas Quadrangle (7.5 min) -
-2 4800670-0'2
Proposed Development
It is our understanding that three-story condominium buildings'with first level
,parking are planned forthe site. It is further our understandin.g that then pre-
sent single terrace will be regraded to 'form two or three terraces which will e-1 1~. step down towards the south. Grading of the terraces would be accomplished by
excavation,and export of soil. Slopes would be eliminated or reduced and re-
taining walls would be constructed to serve as grade separations between terraces.
-1 Subsurface Investigation
Nine test borings.ranging in diameter from 12 to 36 inches were drilled to depths
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of 23 to 42 feet in order to evaluate the subsurface conditions at the site. The
approxima~te boring locations are shown on the Geotechnical Map, Plate 1. The
borings were logged during drilling and downhole logged after drilling, and repre-
sentative bulk and undisturbed samples collected for laboratory analysis. Logs
of the borings are presented in Appendix A.
1
Laboratory Testing
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Laboratory testing was performed on selected bulk and undisturbed samples obtained
from the test borings and included moisture-density, maximum density, expansion
index;direct shear and consolidation. Results of the moisture-densisty tests
areshown on the boring logs.. The remaining test results are presented in Appendix
,.,B. - ..~ .~ ,.. .-,.:
-4- lEIGHToN AND AWKIATES
-I 4800670-02 - 1 FINDINGS
~1. Site Geology
The subject site is underlain by three geologic units. From oldest toyoung- est they are as follows:
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l Delmar Formation (Td)
o Old~alluvium. (oal)
l Compacted.fill (fill)
Delmar Formation: Underlies the entire site and is exposed in the cut slopes
along the eastern and southwestern corners.of the site.~ This bedrock unit
consists of interbedded clay; silty clay, and clayey Andy silty sand. Bedding
within the unit is lense-shaped with individual lithologies not traceable
across the site. In general, the Delmar Formation on the site dips 5 to 20
degrees to the southwest. The existing south-facing cut slope is considered
stable with respect to the exposed bedding conditions.
Old Alluvium: Encountered in'Borings B-l through B-5. The materials consist
of dense, poorly-graded, clean, medium to coarse-grained'sand and thin inter-
:, beds of sandy silt. Colluvial soils composed of- dark brown silt and silty
clay overlyingthe Bl~Tu~vium were encountered in. Borings~B-~2 and Bi3.
Cppacted Fill: Placed in the southeastern portion of the site and locally
a ong the top of the slope bounding the southern edge of the lots. .The
approximate location of the fill is delineated on the Geotechnical Map, Plate
1. These materials consist of silt, silty sand, and sandy clay placed and
compacted under the supervision of Benton Engineering, Inc. in 1970.
2. Soil and Bedrock Conditions
The alluvial and fill soil and bedrock materials (Delmar Formation) encountered
at the site are generally dense, moderately to well compacted or well consoli-
dated and are considered generally favorable with respect to the proposed de-
velopment.
The compaction of existing fill soils should .be further verified by additional
testing at the time of construction. Up to 2 feet of uncontrolled clay fill
is reported as having been placed on portions of Lots 229 and 230 subsequent
to previous grading operations.
Portions of the on-site soils are clayey and expansive and will require
special foundation design where exposed at finished pad grade.
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_j -5- LEIGHTON AND ASSDCIATFS
4800670-02
The bedrock materials at the site, consisting of layered sands and clays,
are generally inclined such as to vary from neutral to approximately 5 de-
grees out-of-slope, with respect to south-facing cuts. As such, earth but-
tress construction,,~would not be necessary unless the bedrock inclination
is found during construction to be locally greater or unless~ a particularly
weak layer; e.g., plastic clay, is encountered. However, the necessity of
some buttressing should be anticipated for south-facing cuts or excavations
for retaining walls.
3.
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Site Hydrology :and'Groundwater
Surface runoff on the,eastern half of the site is directed toward the cut
and fill slopes in the southeastern corner of the site. As a result, the
runoff has created numerous pipes and gullies at the~top of the slope.
Several of the larger gullies extend to the base of the slope. The severe
gullying appears confined primarily to the cut slopes exposing silt and sand
of the Delmar Formation on the easternmost portion of the site. Piping at
the top of the slope is more extensive within the fill materials. Where
runoff is controlled in the western portion of the site the effects of erosion
are minimal.
The southern slope is drained by concrete terrace or bench drains with a 20-
foot vertical separatidn; The bench drains do not extendfo the east-facing
sl.ope. - . ,. '.: '.
No groundwater was encountered during the subsurface investigation. Grading
may expose relatively permeable sand of the Delmar Formation or alluvium.
If irrigation water is allowed into these materials, the southerly dip of
the formational sand may allow migration of the water to the existing south-
facing cut slope creating a potential for seepage.
The i,nterbedded sand and clay bedrock conditions (pervious and impervious
layers) at the site are expected to cause lateral as well as downward migra-
tion of groundwater subsequent~to development. Installation of well-designed
back-drainage systems wills be necessary for retaining walls and it should be
anticipated that portions of cut-slope faces will become wet and will remain
saturated afterdevelopment unless replacement fill, buttress construction
or other remedial measures are undertaken.
Faulting and Seismicity
The two principal seismic considerations for most properties are surface
rupturing of earth materials along fault traces and damage to structures
and foundations due to seismically-induced groundshaking. No active or po-
tentially active faults are known to transect the site. The potential for
damage due to fault surface rupture is considered nil.
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4800670-02
The two faults considered most likely to produce significant groundshaking
at the site are the Elsinore and the Coronado Banks faults. The seismic - effects of groundshaking can be mitigated by adherence to'the provisions
of the Uniform Building Code or Structural Engineers Association of Ca~lifornia. /
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4800670-02
CONCLUSIONS
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3.
4.
From a geotechnical standpoint it is our opinion that the site is suitable
for the proposed development provided the recommendations contained in the
following sections of the report are incorporated.Gthin the design and
construction of the project.
No active or potentially active faults are known to transect the site.
The primary seismic hazard is groundshaking due to the effects of an
earthquake on major active faults in the region.
Existing fill soils encountered in our test borings-were found to be moder-
ately to well compacted. Fill compaction should, however, be further verified
by inspection and, if necessary, testing at the time.of construction.
South-facing cuts or excavations for retaining walls should be evaluated for
stability during construction and in the event of adverse geologic conditions
may require stabilization by earth buttressing or other remedial measures.
LEIGHTON AND ASSOClATfS
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4800670-02
RECOMMENDATIONS
'1. Site Earthwork :.
Site earthwork should proceed in accordance with the provisions, of the
Gener~al Grading and Earthwork Specifications presented in Appendix C.
Excavations of the on-site soils can be accomplished using conventional
earthmoving equipment. AS excavation proceeds in the existing fill areas
of the site; evaluation and, if necessary, testing of the existing fill and
underlying,natural ground should be performed by the geotechnical consul-
tant. If unsatisfactory conditions are exposed (although not anticipated),
overexcavation and recompaction beyond and planned excavation depths should
be performed as directed by the geotechnical consultant.
2.
3.
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The moderate to'deep erosion gullies existing in the slope areas of the
site will likely be removed by proposed excavation. The grading plans,
once completed, should be reviewed to verify that gulley areas will be
removed, and if the gullies are not completely removed by planned excavations,
remedial grading will be necessary.
After removal of brush from the project area, site soils are, in general,
considered suitable as fill material. All excavations for slopes or retain-
i,ng walls should b&inspected by the geotechnical consultant and @here adverse
geologic/soil conditions are exposed, earth buttressing or other remedial
measures should be performed as directed by the geotechnical consultant. The
grading plans should be reviewed in advance of grading to evaluate areas where
the likelihood of buttress construction is greatest. Typical buttress details
are presented in Appendix C.
It may be desirable to stockpile the more sandy soils.encountered during ex-
cavation for use as wall or trench backfill materials.
Slopes
Cut and fill slopes should be constructed no steeper than 2horizontal to 1
vertical. Fill slopes should be compacted by sheepsfoot-rolling or over- building .and cutting back. Appropriate surface drainage features and ?and-
scaping should be provided to minimize any potential for erosion.
Foundations
l Footings
Conventional shallow footings are recommended for support of the pro-
posed condominiums. Continuous and individual footings should be a
minimum of 12 inches wide and 18 inches deep and may be designed for
an allowable soil bearing pressure of 3000 pounds per square foot with
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4800670-02
a one-third increase for all loads including wind or seismic. Where
expansive soils occur within the upper 3 feet of graded building areas,
footings should be reinforced and/or deepened to minimize the potential
for distress resulting from expansive soil pressures.
Floor Slabs-On-Grade
Floor slabs-on-grade should be a minimum for four inches thick (nominal),
and'in living areas, should be underlain by a sand blanket (Z- inch thick
minimum) and a plastic membrane. Floor slabs to be placed over expansive
subgrade soils should be reinforced by welded wire mesh and the subgrade
moisture should be increased, if necessary, such that the moisture con-
tent is equal to or greater than optimum, prior to concrete placement.
Identification of Expansive Soils
Expansive soils where occuring within the upper 3 feet of building areas
after grading, should be tested for swell potential and evaluated by the
geotechnical consultant. Specific foundation recommendations on a build-
ing by building basis sh,ould be determined based on evaluation of the
test results.
Footings Near Slppes .~ -~_~. ~~.i .*..I
Footings near slopes should be set back from the top of the slope or
deepened such that the bottom outside edge of the footing will be a mini-
mum of 8 feet (measured horizontally) from the slope face.
Passive Resistance
The allowable passive pressure for resisting lateral structure movement
may be assumed to be equivalent to the pressure of,a fluid weighing 300
pounds per cubic foot. The coefficient of friction between concrete and
soil may be assumed to be 0.35 for resistance to horizontal movement.
4. Retaininq Walls
Retaining walls free to deflect at the top and resisting lateral earth pres-
sures from on-site soils should be designed for an equivalent fluid soil pres-
sure of 40 pounds per cubic foot for level backfill and 60,pounds per cubic
foot for 2 to 1 sloping backfill conditions. Walls restrained from movement
at the top (e.g. basement walls) should be designed for an equivalent fluid
pressure of~50..pounds Per cubic foot for level backfill and 65 pounds per
cubic foot for 2 to 1 sloping backfill. Any additional surcharge pressures
should be added to these values.
Wall foundations may be designed for the allowable soil bearing values pre-
sented previously for building foundations.
I~IGIITON AND ASSDCIATZI
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5. Pavements
Pavement design should ,be performed on the basis of R-value testing of ex-
posed subgrade soil conditions once the site has been brought to.rough
grade.
Walls should be properly drained with graded filter material and perforated
pipe placed behind the wall to prevent buildup.of hydrostatic water pres-
sures. Basement walls should be fully waterproofed.
4800670-02
This opportunity to be of service is sincerely appreciated. If you have~any
questions, please call.
Respectively,
Martin R. Owen, RCE 23155
Chief Geotechnical Engineer
- ~_~ ,.i .~ ., Dennis L. Hannan, CEG ~$3
Chief Engineering Geologist
MRO/DLH/gb
Distribution: (5) Addressee
(2) Pountney & Young, Inc.
(1) Homer Delawie Associates, AIA
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LEIGHTON AND ASDCIATES
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Date 10/6/80 Drill Hole No. B-l Sheet 1 of 1
Project Name L & M La Costa Valle Uni Project No. 4800670-02 v t No. 5
-Drilling Co. Morrison Drilling Type of Rig Bucket Auger
.Hole Diameter 24" Drive Weight Drop in.
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Ref. or Datum MSL
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GEOTECHNICAL DESCRIPTION I
Logged By LV
Sampled By LV
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PILL: Light gray-brown, damp, dense, very fine
silty sand
NATURAL GROUND:' Dark @@-brown. moist, dense,
very fine silty sand to fine sand
k;;.es of gray, moist, si'lt to slightly sandy
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Gray-brown, mottled orange, damp, dense, fine
sand, friable
Light gray-brown, damp, dense, medium fine sand
with occasional 2" diameter gravel
Grades to fine,medium sand @ 15'
Becomes interbedded in coarse sand @ 15'-20'
Light gray-brown/orange-brown, slightly moist
to moist, slightly gravelly, medium sand with
Borne clay binder.
Total Depth: 23 Feet
No groundwater encountered
No caving
- I CI~Ul-Ah, --A Ac2CAPIATCC
CILUI LlLII.\ ,L.:,I. ~“,<I.\b L”cl -
I’ Dare 10/6/80. Drill Hole No. B-Z Sheet 1 of 2
Project Name L & M La Costa Valley Unit No. 5 Project NO. 4800670-02
- Drilling Co. Morrison Drillinq Type of Rig Bucket Acger
Hole Diameter 24" Drive Weight?,300# to 25'. 1,450# to 50' Drop 12 in.
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112.7
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112.5
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03.5
103.2
Ref.
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GEOTECHNICAL DESCRIPTION
Logged By LV
Sampled By LV
FILL: Light gray-brown, damp, dense, silty
fine sand
Dark gray-brown, moist, medium dense, fine Dark gray-brown, moist, medium dense, fine
sandy silt. sandy silt.
Dark brown, moist, dense, silty fine sand Dark brown, moist, dense, silty fine sand
to fSne sandy silt to fSne sandy silt
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Brown, mottled light blue-gray-brown, moist,
stiff, silty, sandy clay
Yellow, mottled blue, green, gray, red-brown,
moist, very stiff, silty, sandy clay
Light brown, mottled yellow, moist, stiff to
dense, silty, sandy clay-clayey sand
NATURAL/TOPSOIL: Dark brown, moist, stiff silt
with orange chips, old rootlets
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-I Date 10/6/80 Drill Hole No. B-2 Sheet 2 of 2
.Project Name L & M La Costa Valley Unit No. 5 Project No. 4800670-02
_I . Drilling Co. Morrison Drilling Type of Rig Bucket Aucler
.Hole Diameter 24 'I Drive Weight 2,300# to 25', 1,450# to 50' Drop 12 in.
-%levation T
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Ref. r Datum MSL
I;- $ui GEOTECHNICAL OESCRIPTION
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4; z- Sampled By LV
SF Light gray, moist, dense, medium fine sand Light gray, moist, dense, medium fine sand
;
Total Depth: 31 Feet
PO groundwater encountered
I Flr,HTnN arlri ASS~IYATIX
I GEOTECI1NICAL IWIIING LOG
Date 10/6/80 Drill Hole No. B-3 Sheet 1 of 2
I Project Name L & M La Costa Valley Unit No. 5 Project No. 4800670-02
Drilling Co. Morrison Drilling Type of Rig Bucket Auger
' Hole Diameter 24 " Drive Weight2,3DD# to 25', 1,450# to 50' Drop 12 in.
'Ievntinn Tnn nf Hole +79' Ref. or Datlnn r.cI ,-------.. e-r - - - - - ~~.-. __ --_-.. ..--
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a 5ssbo 3 2 L.70 $5 ;e “u; GEDTECmICAL DESCRIPTION
gE 22 ;* 2:: ati- - .:: i-' "a rl zudp UL!
"55. $ cDF4 0.3 .dg-rlv) Logged By LV
2 2 -s m ?c pu 4-J c%:- Sampled By LV. D ~~
0 Z' SM FILL: Medium gray-brown, moist, medium dense, . . 1::. : silty fine sand
; 7.' 1 7 114.3 '9.1 . &_' _. . . . ; . \' 1.' 7.. 2 8 103.2 16.9 SM Orange-brown, moist, very dense, slightly
. :.+
5 ,777.'
clayey, silty, fine to medium sand
.L' . ; . ,. . ML- Gray-brown, mottled orange, moist, very dense,
79; 3 1 9 118.5 11.3, ";. slightly clayey, fine, sandy silt-silty sand
.G, . ..L.. _ . . '1.: . ~77: .~ ,. - 10 '.:.",.. '. -. SM- Medium brown, mottled blue, gray, orange, olive,
.'Y ML moist, very dense, silty fine sand-fine sandy LL - .L 4 7 111.8 14.1 silt
+ :’ ML Medium brown, mottled blue, olive, gray, red,
moist, very stiff, fine,sandy,clayey silt
15--
- -. 5 9 103.3 21.0
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20 ML Medium brown, mottled gray, moist, hard,
- 6 8 113.9 ID.9 clayey silt
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25-L -
- - 7 11 109.7 18.0
. . . _.'_ : SP Yellow, moist, dense, fine to medium sand
: .-. . . - . .
3. :.:.::.
I FIGHTON and ASSOCIATFS
-i GEOTECIINICAL BORING LOG
Date 10/6/80 Drill Hole No. B-3 Sheet 2 of 2
_I Project Name L & M La Costa Valley Unit NO. 5 Project No. 4800670-02
I Drilling Co. Morrison Drilling Type of Rig Bucket Auger
Hole Diameter 24" Drive Weight 1,45D# to 50' Drop 12 in. -:
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um MSL
I CEOTEC~ICAL DESCRiPTION
Logged By LV
Sampled By LV.
)D' -e 8 i13.9 10.9 = - k -
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ML
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ledium brown, mott'ied blue, red and gray, moist,
lard, slightly sandy, clayey silt
IATURAL: Red-brown, moist, very stiff, silty
:lay, colluvium :..;:. . . : y.. .::: ..:p . .:I:: , . . . . . * . . . . .<’ .,?,,i ::‘: :
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SP
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!ed-brown, moist, dense; medium to coarse sand rith some gravel., old alluvium, cross-bedded,
:hanneled . ;...
lark blue-gray-brown, moist, slightly stiff,
elastic clay
'otal Deoth: 42 Feet
IO groundwater encountered
lo caving
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I FICUTnN 2nd A.C.Cf-WYATEC
q / GEOTECIINICAL BORING LOG
' Date 10/6/80 Drill Hole No. B-4 Sheet 1 of 1
-11 Project Name L & M La Costa Valley Unit No. 5 Project No. 4800670-02
' Drilling Co. Morrison Drilling Type of Rig Bucket Auger -
-1
-1
i
lole Diameter 24" Drive Weight 2,3DO# to 25', 1,450# to 50' Drop 12. in.
:levatibn Tc
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i
of Ho1 Ref. or Datum MSL
I I GEOTECHNICAL DESCRIPTION
- O- z Z 7 .:. .: .:. .I : .: . : . . *. -.
fl -
i
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;
- -
5 .12.8 15.9
;- :u :r ,” ;: >- - iii
G
SC
CL
sp
SP
Logged By LV
Sampled By LV
FILL: Light gray, damp, medium stiff, fine 7
sandy si,lt
NATURAL: Medium brown., damp, dense, fine sand
-
7
-
6
5
-
-
5-
10-
15-
2D-
25-
30-
+. - i -2
. . . a. . . : :.::
.< : : :
. ; .,; :,.
:‘...‘..: :;: Pi ‘...
j.. . . . *.
. . . . . ::,
: .f. : :‘. . . . ,.. . . . . ..*:. . . . . . .;. * ::.. a .’ ..* . .
::. . . ..I. . :‘.:’ ;. i : . . : . :
:.:.: :,
i. .:. C. .;:::
.11.8 16.1 Gray, mottled orange, moist, stiff, fine clayey sand-sandy clay
Light gray, slightly damp, dense, slightly
silty, fine to medium sand, friable
-
-
L.
2
-
-
-
_.
.08.9 3.6
Red-brown, damp, dense, medium to coarse sand,
some fine gravel; cross-bedded, friable I
6" to 1' Channel cuts in clay
Pale olive-blue, moist, stiff, fat clay, massive
/
.07.8
-.
ill.4
21.5
16.5
L-
H =
z.Tz -
-
-zE
_-. ,A -
-
-
L Pale olive-blue, moist, stiff, medium, sandy
clay
Total Depth: 25 Feet
No groundwater encountered
No caving
. L
-. *
bLI”1cL,I:\,L:\L biJKl..b L”b -
)I Date 10/7/80 Drill Hole No. B-5 Sheet 1 of 2
Project Name L & M La Costa Valley Unit No. 5 PrOjCCt No. 480()670-02
- Drilling Co. Morri-son Drilling Type of Rig Bucket Auoer
hole Diameter 24" Drive Weight 2.300# to ~25', 1,450# to 50' Drop 17 in.
e +86' Datum MSL ilevation T'
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‘I
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-
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7 * ‘A L. * _-
oj -
2 -2 .: :: < -
, i :, 2; I I tJ
GEOTECHNICAL DESCRIPTION
Logged By LV
Sampled By LV
-
11.0
'ILL: Light gray, damp, medium dense clayey to
silty fine sand
.* .. : . . * . : :.: . . . . . .
Iz
. . .‘L ‘.*;* ’ 5 ;se:;::
'r I -
Ii-
3u
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ZK
CC
F
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.
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j-z - - FT ?I 7 I+-- -:. :; i . -II
2
-
3
4
14
-
I6
-
f+
.21.5 LO.3
Becomes dense to very dense
NATURAL:- Pale yellow-gray, damp, very dense fine to medium sand with some silt binder
gravel at contact
24.9 12.8
Pale violet, slightly damp, very hard, silty
clay to clayey silt; massive
-
ir
;M
/iolet mottled red-brown, damp, very hard clayey
silt with streaks of fine silty sand; massive
25.3 .1.9
-I
4
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‘~ j, - I.‘...’
2 -..:. .:.
%
_., 1“ ..--:.: .. .. - AI -
3-
;*
i$
- -
@ 27' red-brown silt layer 3" thick
I wxri-nhl Qnd A.C.Cf-W-IATCC
-I Date
GEOTECIISICAL BOKING LOG
10/7/80 Drill Hole No. R-5 Sheet 2 of 2
~ Project Name L & M La Costa Valley Unit No. 5 Project No. 4800670-02
Drilling Co. Morrison Drilling Type of Rig Bucket Auger
-
-
-
-
-'
,I
-
-7
,i
1
!
-1 .d
-
-,
I . .
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i ;*
1
Diameter 24" Drive
of Hole 536' -
kz -0 1 .!i :: 4 - -
Weight 1450# Drop 12 in.
ori
15.3
r Datum r Datum MSL MSL
I I n ,-. n - iG i; GEOTECHNICAL DESCRIPTION GEOTECHNICAL DESCRIPTION
;; ;; ,G ,G Logged By Logged By LV LV
;s ;s Sampled By Sampled By LV. LV. 1- 1-
I ML Olive-gray mottled red, brown, purple, moist ML Olive-gray mottled red, brown, purple, moist
hard, sandy clayey silt hard, sandy clayey silt
SM Medium brown, damp, very dense silty very fine
sand
I
SM Medium brown, damp, very dense silty very fine
sand
3ri -
14.3
:z,- Blue gray, moist, very dense, silt - very fine :z,- Blue gray, moist, very dense, silt - very fine
sand sand
.,a, .,a,
Total Depth; Total Depth; 39 Feet 39 Feet
No groundwater encountered No groundwater encountered
No caving No caving
GEOTECMNICAL BORING LOG
* Date 10/7/80 Drill Hole No. B-6 Sheet 1 of 2
- Project Name L & M La Costa Valley Unit No. 5 Project No. 4800670-02
Drilling Co. Morrison Drilling Type of Rig Bucket Auger
- Hole Diameter 24" Drive Weight 2,300# t0 Z5', 1,45O# t0 50'. Drop ._ in. 12
. 1 I J
1
1
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7 d
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of Hoi'
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- -
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16
17
107.6
127.3
Ref. or Datum MSL
I
t!‘; z a< a $t
$6 ‘.
i3.8
GEOTECHNICAL DESCRIPTION
Logged By LV
Sampled By LV
15.1
18.4
13.5
FILL: Blue-gray, moist, stiff, silty clay to
1 clayey silt
-
I NATURAL: 1" thick, dark brown, moist, soft,
j , :lay; old top soil ‘$\ Yledium brown, moist, dense, fine sand
CL I Dlive-gray, moist, soft tomediumz.stiff, silty
, clay
:L I ?ale blue-green, moist, very stiff, slightly
silty clay; massive
:L
- ZL Olive-blue; moist, medium stiff, silty clay
'ale violet mottled orange and red, moist, very
hard, silty clay-clayey silt with streaks of
silty sand
- . -.-a .-A.. * .P.e--. .-.-?^
- ,I GEOTECHNICAL BORING LOG
Date 10/7/80 Drill Hole No. B-6 Sheet 2 of 2
-
,I
Project Name L & M La Costa Valley Unit No. 5 Project No. 4800670-02
Drilling Co. Morrison Drill Tng Type of Rig Bucket Auger
_~ Hole Diameter 24" Drive Weight 1,450# to 50' Drop 12 in.
I
-. ! I
_ii
-,
I ._
- :]
- ,I - ,.,-I - I ,a - ,\ - ,*I - 1 -1 -
[I - -I - ,I L I .- - I
E Ilevation T
1
-
x .:: 2G
GZ x E.
m
r Datum MSL
r;- ;vj GEOTE&ICAL DESCRIPTION
;i
44 Logged By LV
'G :- Sampled By LV
M Dark red, damp, very dense, slightly silty fine
sand; massive
M Medium brown, mottled gray and orange, moist
very hard, 'silty fine 'sand; massive
- Dark blue-gray, moist, very hard, silty fine
f 1 sand; massive
,-,I
Total Depth: 41 Feet
No groundwater encountered
No caving
-
I r=tm-rrnh~ an~ AC.Cnl?lATCC
GEOTECIINICAL BORING LOG
Date 10/7/80 Drill Hole No. 8-7 Sheet I of I
1'
Project Name L & M La Costa Valley Unit No. 5 Project No. 4800670-02
i Drilling Co. Morrison Drillilg Type of Rig Bucket Auqer
Hole Diameter 12" .--, j Drive Weight 2,300# to-25 Drop 12 in.
levation TOD of Ho1 - 8( -
4 ! i' ; I 1
- -
Ref. - - 1
-I I .- ~11
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II
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2z
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04.3
04.7
l-
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i
1
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I‘ Datum MSi
o- -T- i+ CEOTEChNICAL DESCRiPTION I ;;
.G Logged By LV
'S :- Sampled By LV
12.6
:L FILL: Medium brown mottled gray-brown moist
stiff clay to silty~clay 1 to 2" diameter
rocks in upper 1' (IO-15%)
.8.6
-
6
-
-
0
-
;t,
7
-
-
-. 09.1
11.8
21.6
~
,8.8
5~. 7
I :L- NATURAL: Gray-brown, moist, dense, fine sandy
X clay to clayey sand 1 IL- Gray moist, hard, fine sandy silt to sandy clay
:L
IL @ 10-' 1" thick bed of laminated silt
Dark red-brown,~moist, hard, fine sandy silt
@ 13-15' medium sand beds 1-3" thick
IL Dark red brown-maroon, moist, hard, sandy clayey
silt; massive
No caving
1 rIcu-rnht -4 ACCnPIATKC
4, GEOTECHN I CAL Boll 1 NG LOG
~’ Date 10/7/8D Drill Hole No. B-8 Sheet 1 of 1
1
Project Name L & M La Costa Valley Unit No. 5 Project No. 480067D-02
Drilling Co. Morrison Drilling Type of Rig Bucket Auger .
4 Hole Diameter 24" Drive Weight 2,300# to 50' Drop 12 in.
I
7
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--'
10 = ,:,*..:.y, :: .. &'. . c ,. ,I .::
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25-
30
1 -
2
13
-
20
i7
-
10
T -
-
04.8
-
18.5
09.8
Ref. rl -
n' r ;I/
;r -Iv z= ok
-
jM
rum MSL
CEOTECtiNICAL DESCRI'kTION
Logged By LV
Sampled By LV.
NATURAL: Gray moist, very stiff, very fine
sandy silt
Medium brown, mottled ,gray, moist, very stiff
hard, fine silty sand to sandy silt
Dark gray-brown mottled blue-gray and brown
fine sandy silt with gypsum
gypsum seam
Dark orange-brown, moist, very dense, slightly
clayey silty sand
Dark orange-brown hard fine sandy silt; massive
Dark gray moist very dense silty medium sand;
cemented
Total Depth: 24 Feet
No groundwater encountered
Vo caving
I GEOTECIINICAL BORlNG LOG
. Date 8128180 Drill Hole No. B-9 Sheet 1 of 2
- Project Name La Costa Valley Unit No. 5 Project No. 4800670-02
Drilling Co. Anderson Drillinq Type of Rig Watson 60 Soin Auger'
,- , hole Diameter 36" Drive Weight I,200# Drop 12 in.
>,’
-
.-.
a
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rl Ref. - um MSL levation Top levation Top
5:: 5::
ak. g:' ak. g:'
CM .," CM .,"
mas mas G G
0 0
5 $ 5 $ ~I- ~I-
J J
J J
lo- lo-
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1 4 1 4 ~_ ~_
2e- 2e-
25 25
38 38
of Ho18
2
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-
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$F
GEOTECHNICAL DESCRIPTION
Logged By SRH
Sampled By SRH
ILL: Gray-green,~ stiff sandy clay to clayey
tnd, dry
LLL: Red-brown dense clayey fine sand, damp,
? oxide stains
-
ILL: Gray-brown, clayey silty sand, dense,
)ist
LLL: Yellow-brown to gray-brown, silty fine
md, dense, moist
3
- -
:L
i- ,L
\
X
P
LLL: Light brown, sandy stiff clay, damp
ILL: Green-gray slightly sandy clay, stiff,
list, lenses of orange-brown coarse sand
:LL: Yellow-brown, clayey sand, dense, damp.
kerbedded with gray sandstone
nL: Gray-white, silty, fine sand, dense, dry -
.-.-..--.. _----
-II GEOTECIINICAL BORING LOG
Date a/78/80 Drill Hole No. B-9 Sheet 2 Of3
d Project Name La Costa Valley Unit No. 5 Project~No. 480()670-02
Drilling Co. Anderson Drilling Type of Rig Watson 60 Spin Auqer
_;: Hole Diameter 36" Drive Weight Drop in.
2
‘-2
-1
1
1
L
,L
L
7
I /
i
r
r
I-
t
.levation T
" 5'3 ';~M g: ,a2
c
nt5. 2
30
J
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J
40-j
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op of Hoi'
2 Tl 3
.z
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-
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:
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-
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-
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-
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Ref.
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r I -
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r P , -
X
-
- 1P
:um
GEOTECHNICAL DESCRIPTION
Logged By SRH
Sampled By SRH
:ILL: Gray-white, silty fine sand, dense, dry
:ILL: Orange-brown, slightly clayey, coarse,
;ilty, sand, medium dense, .damp
IATURAL: Gray to dark brown, soft, slightly
;andy clay, moist.
;rading into gray-brownclayey dense sand !z34' 35'
Irange-brown coarse sand, medium dense, damp.
locks= %" to l'! in diameter. ;
iota1 Depth: 43 Feet
to groundwater encountered
;:‘,,,“~~:;~.;‘,,~~p-,,1,~. :. pi, :; ‘~‘, :~,‘~,i”,:i,’ i : : ;,, L .,.!..,~ ,.., &..@,< .ii .‘..,~ib’~ :.., ,:: ,,, ~,:~-j.,~~~,,,:,di,j,~;?~:.‘--. :. ;.~ :,:’ :.
*i~~:..~~~~~~.!~,:~;;;;i.:.,-,:~ :~: ‘_,
;: i~..:~~~~~~~~-“:l:i~~:;~:-:::i::’~, ;,,:,,,, :,:i :;;:m,:;i ,:.~~,!c~~~~,:~.-.;:: .., ,,, s
:.I : ,#
i ; ,; !,,: ~(~i; $fi, ,!i.;;,>>’ ,_: ~.:, /: A;,. ;,,~
~i:~.,,..r.~~~-,;~~ 4, I,,.. ::,::+;;.~ :, ,.‘.;y,;;t ,+:.. 1,:’ ~’ 6 ”
~ii~~.::~,~~~~~~~~~~~~~~~~~~~~ f;; :: :;‘{, $: my ‘;; ;:$:I. :~y::f:;: $ :::’ ‘j
:,I
I .,‘,.,‘.. .,,~ ::y.,:. :,~ ,z<,,~,;~s,;; ~: ~~i’:‘L”::~~~~:~~,,‘.~~?~~j~;~:l_: ‘;: :: ,, ;
:I 1’ ;;~, : ,:: ,j,, .,,~~ ‘, ,( ;::, ‘~;;
.J/ a,/ j.’
:, ~,.. i.,
.., APPENDIX B
MAXIMUM DENSITY TEST RESULTS I
SOIL
OESCRlPTlON
OPTIMUM
MOISTURE(‘=JJ MAXIMUM
DRY DENSITY (PCF)
L I B-2 Q 8’ Dark brown silty fine sand
Ii, a-2 @ ~15’ Brown mottled blue silty, sandy
clay
1:
B-6 @ 1' ~Blue-gray silty clay/clayey silt
I
Ii
12.0 124.0 I
12.5. .~ 1’18.5
12.5 121.0
FXPANSION INI-IFX TFST RFSIIITS I -,.. . .._-.-.. .._--.. .--. ..----.- .
SAMPLE INITIAL COMPACTED DRY FINAL VOLUMETRIC EXPANSION EXPANSIVE
LOCATION MOISTURE 1%) DENSITY (P CF) MOISTURE(%) SWELL(%) INDEX -- CLASSIFICATION -
,.
Low to B-1 @ 2' 6.7 107.5 20.3 4.4 44 Moderate
B-2 @ 8’ 4.4 107.0 la.4 1.7 17 Low
B-6 @ 1’ 58 Moderate
-.jec? No: 480067b-02 I -.-L. n .----:-.-- Plate No: B-l
DIRECT SHEAR SUMMARY
5 C~ I i I I, 1
t ~’
I I I I I I I I I ’ 230
2000 J 2000 J 1 I 1 I I I I I I I I I I I I I 210 IJ 210 IJ
I I I I I I I I I I I I I I I I ‘~ 210 _ ‘~ 210 _ s s I
100
ISO gf
1.0 D
I!
110 ,,OO g
: 160
150 -. I ! I / / // I40
! I Y / - /I / -130
I I / I/ I 120 I I i I / A I I 1
i
I : I/Y / I I I Y I/ I I I : /I ;/ I I 100
/ I H/n -.- I I
NORMAL STRESS, PSF
Boring Depth Symbol Friction Angle Cohesion Remarks
B-2
B-3
~ lj'-7' A 3a" 200 psf
3'-A' 0 28' 400 spf
'L. iart Nn t 480067~n7 I -T-C.- n .---_:-.-- _,_.~ L. D 3
CONSOLIDATION - PRESSURE CURVE
PRESSURE (Kips per Square Foot)
0.05 0.1 0.5 1.0 5.0 10.0 K
I’ I’
I I
I I
- j - j
-t -t
_’ _’ I I
-I -I
ml ml
-1 -1
- - I I
j j
yl yl
..- ..-
.- .- - -
-
J
1 I I
i
4
‘reject No.: 4800670-02 Plots No.: B-3
Lninhtnn R A?;snr.iatns
I.0
7
0 Indicates Sample l Indicates Sample
At Field Moisture After Saturation
-,
.,
-; ..:.,L ,. ;~ .,. ! ., , : - ~Ij - ,I ~‘I,,
- ,I APPENDIX C .
4%
bl LEtaHTON and AssoclATES .._ --- --.---
-I
-I
4
i
.-
t
-,-I
1
3 I
-J
3
_I
_I
_1
-I
1
1
I
I
GENERAL GRAAIEG AND EARTHWORK SPECIFICATIONS
1. Scope ?
: a. This section contains general specifications for work relating to the
following construction:
Site Clearing and Grubbing
Preparation of Subgrade in Areas to be Filled
Placement ~of Fill
Subdrains
Trench Backfil.1
b) The owner shall employ a qualified soil engineer to-inspect and test
the fill as placed to verify the uniformity of compaction to the spec-
' ified density ,requirement. The soil engineer shall advise the owner
and grading contractor immediately if any unsatisfactory soil related
conditions exist and shall have the authority to reject the compacted
fill ground until such time as corrective measures necessary are taken
to comply with the specifications. It shall be the sole responsibility
of the grading contractor to achieve the specified degree of compaction.
2. Clearing, Grubbing and Preparing Areas to be Filled
a)
b)
cl
d)
All brush'iegetati'on, rubbish and desiccated top clay oil shall be
removed, piled, or otherwise disposed of'so as to leave the areas to
be filled free of vegetation, debris and desiccated top clay soil.
Any soft and swampy spots in the canyon areas shall be corrected by
draining or by removal of the unsuitable materials.
The natural ground which is determined to be satisfactory for the sup-
port of the filled ground shall then be plowed or scarified to a,depth
of at least six inches (6") and until the surface is free from ruts,
hunmocks, or other uneven features which would tend to prevent uniform
compaction by the equipment to be used. The scarified ground should
be compacted to at least 90 percent of the maximum laboratory density.
Where undisturbed bedrock is exposed at the surface, scarification and
recompaction may not be required.
Where fills are made on hillsides or exposed slope areas, the existing
top unstable materials should be removed. If existing slopes are
steeper than 5 horizontal to 1 vertical, horizontal benches shall be
cut into firm and competent undisturbed soil or bedrock in order to
provide both lateral 'and vertical stability. (See benching detail
page VIII of this Appendix.)
All areas to receive controlled fill, including all removal areas and
toe-of-fill benches, shall be inspected and approved by the soil
engineer and/or engineering geologist prior to placing controlled com-
pacted fill.
a
i
-1
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4.. Placing, Spreading and Compacting Fill Materials-~ . . .
al The suitable fill material shall be placed in approximately level
layers which, when compacted, shall not exceed six inches. Each
layer shall be spread evenly and shall be thoroughly mixed during the
spreading to insure uniformity of material and moisture in each layer.
b) When the moisture content of the fill material is below that specified
by the soil engineer, water shall be added until the moisture content
is near optimum as specified by the soil engineer to assure thorough
bonding during the compacting process.
cl When the moisture content of the fill material is above that speci-
fied by the soil engineer, the fill material shall be aerated by
blending and scarifying or other satisfactory methods until the mois-
ture content is near optimum as specified by the soil engineer.
d) After each layer has been placed, mixed, and spread.evenly. it shall
be thoroughly compacted to not less than 90 percent of maximum density
in accordance with ASTM D1557-70 (five,layers). Compaction shall be
accomplished with sheepsfoot rollers, multiple wheel pneumatic-tired
rollers or other approved types of compaction equipment. Rollers
shall be of such design that they will be able to compact the fill
material to the specified density.
3. Fill Materials and Special Requirements -__- -----
The fill soils shall consist of select materials approved by the project
soil engineer or his representative. These materials may.b,e obtained
from the excavation areas and any other approved sources and by blending '
soils from one or more sources. The material used shall be free from
organic vegetable matter and other deleterious substances, and shall not
contain rock,s or lumps of greater than eight inches in diameter within a
~distance of ten feet from any finished compacted surface. If excessive
vegetation, rocks, or soil with inadequate strength or other unacceptable
physical characteristics are encountered, these shall be disposed ,of.
During grading operation, if potential problem soils are found, these
soils shall be tested to determine their physical characteristics. Any special treatment recommended shall become an addendum to these specifica-
tions. Boulders greater than eight inches but less than or equal to two
feet in diameter should be uniformly distributed in the-compacted fill
areas but no closer than tenfeet from final. grade and should be sur-
..rounded with suffirient amounts of compacted finer-grained materials. No
nesting will be permitted. Boulders greater than two feet in diameter
shall be placed in approved disposal areas no closer than ten feet from
final grade and shall be placed in windrows in such a manner that voids
will not exist around boulders. (See rock disposal detail, page ix of
this Appendix.) Continuous inspection by the project soil, engineer is
required during rock disposal operations.
ii
-1
-
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-
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-
-
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-
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.-
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-
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-
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-1
e)
f)
9)
Special mixing and watering effort may be required where diatomaceous
materials are encountered to achieve the recommended moisture contents
and density.
Fili slopes shall be compacted by means of sheepsfoot rollers or '
other suitable equipment. Compacting of the slopes shall be accom-
plished by backrolling the slopes in increments' of three to~.~five feet
in elevation gain or by other methods producing satisfactory results.
Relative compaction shall be at least 90 percent to the finished
slope face.
The soil engineer and/or his designated representative shall observe
the placement of fill and shall take sufficient tests to provide an
opinion on the uniformity and degree of compaction being obtained.
5. ~Subdrains
~.-a) All naterials.used in the construction of the subdrain systems shall
be of the required types and sizes shown on the drawings or approved
by the soil engineer. Canyon subdrains shall be constructed as shown
on the attached drawing, Canyon Subdrain Construction (page vii of
this Appendix).
b) All drain lines shall be installed to confotm to the.grades and align-
ment shown on the drawing. Modifications of the subdrain layout as
may be required .inthe- field must be approved by the soil engineer and
civil engineer;
cl The subdrain pipe (perforated and non-perforated) shall be approved
by the soil engineer. If the diameter pipe called for on the drawing
is not available in the material chosen by the contractor, the next
size larger pipe available shal~l be used in its place at no additional
cost to the owner.
d) Prior to backfilling, the locations of all drains shall be surveyed
by the civil engineer. It is imperative that the subdrain outlets
be kept clear during grading to avoid damage to the exposed pipe.
e) The fill operation shall be continued to six-inch compacted layers,
as,specified above, until the fill has been brought,@ the finished
slopes.and grades as shown on the accepted plan.
6. Trench Backfills
a)
b)
Trench excavations for utility pipes shall be backfilled under engi-
neering supervision.~
After the utility pipe has been lain, the space under and around the
pipe shall be backfilled with clean sand or approved granular soil
to a depth of at least one foot over the top of the pipe. The sand
backfill shall be uniformly jetted into place before the controlled
backfill is placed over the sand.
. . . 111
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cl
d)
e)
The on-site materials, or other soils approved by the soil engineer,
shall be watered and mixed as necessary prior to placement in lifts
over the sand backfill.
The controlled backfill shall be compacted to at least~90 percent of
the maximum laboratory density as determined by the ASTM compaction
method described above.
Field density tests and inspection of the backfill procedures shall
be made by the soil engineer during backfilling to see that proper
moisture content and uniform compaction is being maintained. The
contractor <hall orovide test holes and exoloratorv oits as reouired
by the soil engineer to
7. .Geologic Inspections
enable sampling and testing.'
~'.a) Graded slopes.are to be periodically inspected by the engineering
geologist to provide an opinion on the stability of excavated slopes.
b) Inspection of excavations other than cut slopes may be required to
refine geologic parameters related to fault hazards, landslide
hazards, or other geotechnfcal hazards that may be indicated.
c) Surcharged cuts are to be inspected by the engineering geologist prior
'to placement of .the surcharge fill prism. .~ ,i
d) Canyon cleanouts will be inspected by the engineering geologist prior
to subdrain placement or placement of fill.
e) Buttress keys will be inspected by the engineering geologist prior to
placement of the buttress fill.
iv
LEIGHTON AND ASSOCIATES
nPlCt\L i?!l~i’iZi:SS Sly.LI iO:;S --. __~- ~.-- -~~_ .-__ i
- I
4:
-1
-i
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Gcncral Ruttrcss Fill Section --
d15’ nin--
1 _..,
1
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-I
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I I----- IV ----I ,’
. . . ‘.
D and IV DETEFWINED BY DESIGti
b max
fill blanket as
ncedcd
Subdrain - See “Huttr
Subdrnin Detail”
Belching
Small Buttress Section
4” diameter outlet iipc
horizontal inter\fals
\ .k 30” compctcd fill H = 20 ft. ln>T . . ..^ blanket as necdcd
1’ clr
1
:d
‘CSS
Subdrnin - See “Btrttrcss Subdrain Detail”
V
- I 4” min. diam. sol~id outlet
pipe splccd at 100’ hori:ontal
intervals.
perforated pipe
(perforations dol:n)
minimum 25. gridicnt
-_ to outlet. A&llr:. ~Gradicnt
A,,
Uench inclined toward
drain
Typical benching.
.._
Temporary fill lcvcl
NETHOD 6 METHOD A
Compacted backfill
6” ?iin. sclcct bedding
backfill
solid outlet pipe
DETAlL A-A
-
I’
Filter materi to meet following Approved Pi pc T\~c.s :
.spccification or approved cquxl: 1. Schedule 40 PoTVinyl-
Chloride - il Sieve Site Prrccntapc Passing 1” .__....._ _ . . . . . 100 2.
.J 3/4”. . -. . . . _. . _. .90-100 ‘I
Corrllpatrd Uct31 Pipe l-lg:l.
6” AC dipped
Alwlinum CorruCztcd.Pipc 1000 gsi AC dil>ped
Acrylonitrilc Putndincnnc Styrcnc
Schc~l~lc .lO, 900 psi
-j[
S/8”. . _ _. . . _. . _. .40- 100
No.4.............25-40
No.B.............lS-33
,No.30 .__.___; _.._ S-15
-; 1 No.50 _......e.. ;.O-.7
No.200.. ..~-. _ _. .:0-S
a.
4.
I
,I.. -. G
1 i
7 ,::I - il
-ii
-11
3 - II - II
1 J
jr:
7 . .
Typical bcnchi
See dc
CAh’YON SUYDRAIN DliTAl IS
Surface of firm --~__-__- L- earth material
ng Remove unsuitable
tail bclow&< Incline toward drain
Method A
DETAIL
ed
ing
. dens.
Filter material to meet following
specification or approved equal:
Sieve Sire P~ercentase PassinK
1 ” . . . . . . . . ..e..-. 100
3/4” ............ .90-100
3/8”. . - -. . _ _ _. . _ -40-100
No.4.............25-4 0
No.8.............18-3 3
No.3O............S-l5
No.SO............O- 7
No.200...........0- 3
Approved Pi,oc T!~cs: -
1. Schcdul~ 40 Poly-Vinyl-
Chloride
2, Corruvntcd Zlctal Pipe llga.
6°K dipped
3. Aluminum Corrug3tcd Pipe
1000 psi AC dipped
4. Acrylonitrilc Gutndicnnc
Styrcnc Schcdulc 40, 900 psi
vii
BENCHING DETAIL
TOE OF- SLOPE
TOP OF FILL SLOPE
I
__---- c-
c/ /- /--
_-- >--
15’MlN -------+I
.BASE KEY WIDTH
(INCLINED 2% MIN. INTO sLOPEI : -
Mm&g&
LElGHTON and ASSOCI*TIS IIT,.o..nD-.p^
. . . Vlll
I . I-,uLn tlibvC)bi4L us: 1 hII_ - -.-~---.~.~~
I (BOULDERS GREATER THAN TWO
-
I FEET IN DIAMETER)
,, GUlLDING
I
‘FINISH GRADE \
j CLEAR AREA FOR FOUNDATIONS.
UTILITIES,AND POOLS
II WI HDROW
I
L
I
4
. . .
\ .’
\’ ---
-T
IO OR BELOW DEPTH
OF DEEPEST UTILITY
TRENCH WHICHEVER DEEM
4
TYPICAL WINDROW DETAIL (ED’2
,. i
CLEAN (S.E 130
E VIEW) RANULAR SOIL FLOODED TO FILL
VOIDS
J \
\
HORIZ. PLACED
COfJPACTED FILL
PROFILE VIEW
-
-
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--%2
TRANSITION, LOTS
CUT LOT
-- /-’
_/--- _/---
//--- co\\uvium * oI creep _-- 7opsd s /.YHR
/”
./.
Original Ground
I/- /R \?
./ /yc Overexcavate ond recomppct
/‘-
Unweathered bedrotik or moteriol
opproved by soil engineer
.._ ‘.
CUT- FILL LOT
p Origino,l Ground
5’1 1
Compoded fill ,,I~~ ,> ,
ok cfeeP,c I .- //)j 50”
/M /-
$ -r /- /- co\‘” \i\\lP * /=---- Overexcovote and recompoct
~opsd\‘;.Y;H
I c- Unweofhered bedrock or moferiol
opproved by soil engineer
. *
X
$TAB IL~zATION FILL IN PORTION Q.F CUT SLOPE
Natural Ground
,//6nished Grade 0 ,m I
A”-/&eFFUnw!btherid bedrock
_M’ ^ Dacted fill or material approved
by the soil engineer
Note : I. Subdrains-not required unle~ss specified,
2.“W” shall be specified by the soil englneer ’ ‘1