HomeMy WebLinkAboutCT 02-01; PACIFIC VIEW CONDOMINIUMS; GEOTECH INV PROPOSED PACIFIC VIEW CONDOS; 2002-06-24ALLIED EARTH TECHNOLOGY
P.O.BOX 1932 • EL CAJON, CALIFORNIA 92022-1932
„^ TELEPHONE(619)447-4747
ROBERT CHAN, P.E. ^ ^
GEOTECHNICAL INVESTIGATION
PROPOSED CONDOMINIUM BUILDING SITE
SOUTHEAST CORNER OF CARLSBAD BOULEVARD
AND JUNIPER AVENUE
CARLSBAD, CALIFORNIA
FOR
MR. JAMES ZATHAS
PROJECT NO. 02-1106E7
.TUNE 24,2002
ALLIED EARTH TECHNOLOGY
ROBERT CHAN, RE.
P.O.BOX 1932 • EL CAJON, CALIFORNIA 92022-1932
TELEPH0NE(619)447-4747
June 24, 2002
Mr. James Zathas
11905 Riverside Drive
Lakeside, CA. 92040
Subject: Project No. 02-1106E7
Geotechnical Investigation
Proposed Condominium Building Site
Southeast Comer of Carlsbad Boulevard and Juniper Avenue
Carlsbad, Califomia
Dear Mr. Zathas:
In accordance with your request and authorization, we have completed the geotechnical
investigation for the proposed condominium building site on subject property, more
specifically referred to as being Lot Nos. 1, 2 and 3, in Block E of Palisade, according to
Map thereof No. 1747, in the City of Carlsbad, State of Califomia.
We are pleased to submit the accompanying geotechnical investigation report to present
our findings, conclusions and recommendations relative to the development of the project
site.
The investigation was conducted under the supervision of the undersigned. The scope of
our investigation included field exploration, laboratory testing and geotechnical analysis.
No adverse geotechnical conditions were encountered which would prohibit the
development of the site, provided that the recommendations presented herein are
followed.
This opportunity to be of service is sincerely appreciated. Should you have any questions
regarding the contents of this report, please do not hesitate to contact our office.
^.MspectfuUy subjnitted,
ALLIED EARTH TECHNOLOGY EARTH1
an
'd Civil Engineer
Geotechnical Engineer
TABLE OF CONTENTS
Page No.
INTRODUCTION 1
DESCRIPTION OF PROJECT 1
SCOPE OF WORK 1
FIELD INVESTIGATION 2
LABORATORY TESTS 3
SITE DESCRIPTION 4
SITE GEOLOGY AND SUBSURFACE SOIL CONDITIONS 4
GROUNDWATER 4
TECTONIC SETTING 4
GEOLOGIC HAZARDS
Groimdshaking 5
Liquefaction Potential 5
Landslides 6
FINDINGS, CONCLUSIONS AND RECOMMENDATIONS
General 6
Grading 7
Foundation and Slab Design 8
Retaining Wall Design 9
TABLE OF CONTENTS (Cont'nd)
Lateral Loading 10
Temporary Excavations 10
UBC Seismic Coefficients 11
Preliminary Stmctural Pavement Section 12
Concrete Flatwork 12
Backfill Over Utility Trenches 13
Surface Drainage and Maintenance 13
Grading and Foundation Plan Review 13
LIMITATION AND UNIFORMITY OF CONDITIONS 14
Figure No. 1 - Site Location Map
Figure No. 2 - Approximate Location of Exploratory Trenches
Figure Nos. 3 to 5, inclusive - Trench Log Sheet
Appendix I - General Grading and Earthwork Specifications
Appendix II - Laboratory Tests
ALLIED EARTH TECHNOLOGY
P.O.BOX 1932 . EL CAJON, CALIFORNIA 92022-1932
TELEPHONE(619)447-4747
ROBERT CHAN, RE.
June 24,2002
GEOTECHNICAL INVESTIGATION
INTRODUCTION
This report presents the findings and conclusions of a geotechnical investigation
conducted at the site of a proposed six-unit condominium building on subject property,
located in the southeast comer of Carlsbad Boulevard and Juniper Avenue, in the City of
Carlsbad, State of Califomia.
Subject property is more specifically referred to as being Lot Nos. 1, 2 and 3, in
Block E of Palisade, according to Map thereof No. 1747, in the City of Carlsbad, State of
Califomia.
The location ofthe property is shown on Figure No. 1, entitled, "Site Location
Map".
DESCRIPTION OF PROJECT
It is our understanding that a 6-unit condominium building is proposed for the
site. The proposed stmcture will be two stories in height, with a partial basement.
SCOPE OF WORK
The objectives of the investigation were as follows :
ProjectNo. 02-1106E7 Mr. James Zathas 06/24/02 Page 2
1. To inspect and determine the subsurface geotechical conditions and certain
physical engineering properties of the soils beneath the site.
2. Evaluate any potential adverse geotechnical conditions that could affect the
development of the site as accomplished.
3. Provide engineering recommendations for the safe and economical development
of the site.
In order to accomplish these objectives, three exploratory trenches were
excavated and inspected, and representative samples of the subsurface soils were
collected for laboratory testing and analysis.
The data derived from our field observations and the laboratory test results were
reviewed and analyzed, and a summary of our preliminary findings, opinions and
recommendations is presented in this report.
FIELD INVESTIGATION
The field exploratory phase of our investigation was performed on June 4,2002,
and involved the excavation of three exploratory trenches at locations as determined by
our field personnel. The exploratory trenches were excavated with a Case-580 backhoe
equipped with a 24-inch bucket.. The exploratory trenches were excavated to depths
varying from 5.0 to 10.5 feet below existing ground surface. The approximate location of
the exploratory trenches is shown on Figure No. 2, entitled, "Approximate Location of
ProjectNo. 02-1106E7 Mr. James Zathas 06/24/02 Page 3
Exploratory Trenches".
The trenching operation was performed by our field personnel, and a continuous
log of the soil types encountered in the exploratory trenches was recorded at the time of
excavation, and is shown on Figure Nos. 3 to 5, inclusive, each entitled, "Trench Log
Sheet".
The soils were visually and texturally classified by the field identification
procedures set forth on the Unified Soil Classification Chart. Representative samples
were obtained and in-situ density tests performed at various depths in the exploratory
trenches.
LABORATORY TESTS
The samples collected during our field investigation were subjected to various
tests in the laboratory to evaluate their engineering characteristics. The tests were
performed in accordance with A.S.T.M. testing standards or other regulatory agency
testing procedures. A summary of the tests that were performed and the final test results
are presented in Appendix II hereto.
The tests that were performed included determinations of the maximum dry
densities and optimum moisture contents, as well as the Expansion Indices ofthe soils
encountered.
ProjectNo. 02-1106E7 Mr. James Zathas 06/24/02 Page 4
SITE DESCRIPTION
Subject property is a rectangular-shaped lot of approximately 10,890 square feet,
located in the southeast comer of Carlsbad Boulevard and Juniper Avenue, in the City of
Carlsbad, State of Califomia. The general topography ofthe site may be described as
sloping gently in an easterly direction at gradients on the order of 3 to 4 percent. The site
is currently vacant, and had been recently cleared and gmbbed.
SITE GEOLOGY AND SUBSURFACE SOIL CONDITIONS
A review ofthe geologic map of the San Marcos Quadrangle indicates that the
general area is underlain by Quatemary-age terrace deposits. These terrace deposits were
encountered on the site in the form of medium dense to dense, light brown to reddish
brown fine sands and silty fine sands. The terrace deposits were overlain by a 2-foot
layer of loose topsoils, consisting of medium dark brown sands.
GROUNDWATER
No groundwater was encountered in the exploratory trenches to the maximum
depth of exploration at 10.5 feet.
TECTONIC SETTING
No evidence of faulting was noted during our surface reconnaissance or in our
exploratory trenches. A review of available geologic literature did not reveal any major
faulting in the area. It should be noted that much of southem Califomia, including the
City of Carlsbad area, is characterized by a series of Quatemary-age fault zones which
ProjectNo. 02-1106E7 Mr. James Zathas 06/24/02 Page 5
typically strike in a northerly direction. Some of these fault zones (and the individual
faults within the zone) are classified as active, while others are classified as only
potentially active according to the criteria of the Califomia Division of
Mines and Geology.
A review of available geologic maps indicate that the subject property is
approximately 9.0 km (5.6 miles) southeast of the active Newport-Inglewood Fault Zone
(Type B Fault), and approximately 37.9 km (23.6 miles) southwest of the active
Elsinore Fault Zone (Type A Fault).
GEOLOGIC HAZARDS
Groundshaking - The most likely geologic hazard to affect the site is groundshaking as
a result of movement along one of the active fault zones mentioned above. Constmction
in accordance with the minimum standards of the Uniform Building Code and
requirements of the goveming jurisdiction should minimize potential stmctural damage
due to seismic activity. Seismic soil coefficients in accordance with the current Uniform
Building Code were determined with the UBCSEIS Program and presented herein.
Liquefaction Potential - Soil liquefaction is a phenomenon whereby a loose
(unconsolidated) cohesionless saturated soil loses its shear strength (liquefies) during
periods of oscillatory ground motion caused by an event such as an earthquake.
Liquefied soils undergo significant loss in support capacity, which can result in rapid
settlement of stmctures. Soils prone to liquefaction consist of poorly consolidated sands
ProjectNo. 02-1106E7 Mr. James Zathas 06/24/02 Page 6
and sandy silts in areas of high groundwater.
In consideration of the medium dense to dense terrace deposits underlying the
site, it is our opinion that soil liquefaction does not present a significant geotechnical
hazard to the proposed site development.
Landslides - The site is situated on relatively level terrain and underlain by stable
formational soils. A review of the pertinent geologic maps did not reveal any recorded
landslides on subject and adjacent properties. The potential for any landslides as a result
of the proposed site development is considered to be negligible.
FINDINGS, CONCLUSIONS AND RECOMMENDATIONS
General
1. Based on the results of the investigation it is our opinion that the current
site development is feasible from a geotechnical engineering standpoint,
provided that the recommendations presented in this report are incorporated into
the design plan(s) and are properly implemented during the constmction phase.
2. All of the soils encountered on the site are suitable for use as supporting materials
for the proposed improvements, provided that the recommendations presented
herein are followed..
3. The soils encountered on the site possess low expansion potential (Expansion
Index = 25).
ProjectNo. 02-1106E7 Mr. James Zathas 06/24/02 Page 7
Grading
4. It is recommended that all earthwork be accomplished in accordance with the
Grading Ordinance ofthe City of Carlsbad, UBC Chapter A33, Appendix I
attached hereto, entitled, "General Grading and Earthwork Specifications", and
recommendations as presented in this Section.
5. Where the recommendations of this Section of the report conflict with those of
Appendix I, this Section ofthe report takes precedence.
6. Grading operation should begin with any additional clearing and gmbbing of the
site, and hauling of the debris offsite to an approved disposal site.
7. After clearing and gmbbing of the site is completed, it is recommended that the
loose topsoils similar to those encountered in all trench locations to a depth of
2 feet that remain below finished grade be removed. The area of removal should
extend 5 feet outside the foundation line ofthe proposed stmcture and parking
and driveway areas. The bottom of the excavation should be inspected by our
firm. The removed soils should then be properly moistened, and uniformly
recompacted prior to the placement of additional fill soils.
8. All fill soils should be properly moistened, and uniformly compacted in lifts on
the order of 6 to 8 inches until finished grade is achieved. All fill soils should be
compacted to at least 90 percent of maximum dry density in accordance with
A.S.T.M. D1557.
ProjectNo. 02-1106E7 Mr. James Zathas 06/24/02 Page 8
Foundation and Slab Design
9. It is recommended that a safe allowable soil bearing value of 1,500 pounds per
square foot be used in the design and checking of continuous or spread footings
that are a minimum of 12 inches and 24 inches in minimum horizontal dimension,
and are embedded at least 12 inches (for single story) and 18 inches (for two-
stories) below the surface of the competent natural or uniformly compacted fill
soils.
10. The above safe allowable soil bearing value may be increased 300 pounds per
square foot for each additional foot of depth and width to a maximum of 2,400
pounds per square foot.
11. The above safe allowable soil bearing value may be further increased by one third
when considering wind and/or seismic forces.
12. The settlement of foundations, when designed and loaded as outlined above, is
within acceptable tolerance limits for light residental stmctures ofthis type.
13. It is recommended that all continuous footings be reinforced with four #5 rebars;
two rebars located near the top, and the other two rebars near the bottom of the
footing. Spread footings should be 24 inches in minimum horizontal dimension,
and reinforced with a minimum of 2 #5 rebars each, in both directions, placed
near the bottom of footing.
ProjectNo. 02-1106E7 Mr. James Zathas 06/24/02 Page 9
14. The concrete slab-on-grade should be 4 inches net in thickness, and be reinforced
with #3 rebars @ 24 inches on center, placed at mid-height of slab. The concrete
slab should be underlain by 4 inches of clean sand. In areas to be tiled or
carpeted, a visqueen-type moisture barrier should be placed at grade and be
overlain by one inch of protective sand cover. This moisture barrier should be
heavily overlapped or sealed at splices. Please note that the foundation and slab
reinforcements are based on soil characteristics, and should be superseded by any
requirements of the project architect.
15. It is recommended that the foundation trench excavations for the proposed
stmcture be inspected by our firm to ensure proper embedment into competent
natural or compacted fill soils.
Retaining Wail Design
16. It is recommended that retaining walls be designed to withstand the pressure
exerted by an equivalent fluid weight of 35 pcf This value assumes that the
retaining walls are unrestrained from movement, have a granular backfill and
level backfill surface. For retaining walls restrained from movement at the top,
such as basement retaining walls, an uniform horizontal pressure of 7H (where H
is the height of the retaining wall in feet) should be applied in addition to the
active pressure recommended above.
17. All retaining walls should be supplied with a backfill drainage system adequate to
ProjectNo. 02-1106E7 Mr. James Zathas 06/24/02 Page 10
prevent the buildup of hydrostatic pressure. The subdrain should consist of %
inch gravel and a perforated pipe near the bottom of the retaining wall. The width
ofthis subdrain should be at least 12 inches, and extend at least 2/3 the height of
the retaining wall. The subdrain should be enclosed in a geotextile fabric such as
Mirafi HON or equal.
18. The on-site soil conditions are such that cantilever-type retaining walls such as
those presented in the Regional Standard Drawings or the City of Carlsbad
Building Department may be used, where appropriate.
Lateral Loading
19. To resist lateral loads, it is recommended that the pressure exerted by an
equivalent fluid weight of 300 pcf be used for footings or shear keys poured neat
against properly compacted fill soils, or dense undisturbed natural soils. The
upper 12 inches of material in areas not protected by floor slabs or pavement
should not be included in the design for passive resistance. This value assumes
that the horizontal distance of the soil mass extends at least 10 feet or three times
the height of the surface generating the passive pressure, whichever is greater.
Temporary Excavations
20. Excavation for the proposed basement retaining walls may be accomplished at a
near-vertical inclination up to a maximum height of 5 feet. Above a height of 5
ProjectNo. 02-1106E7 Mr. James Zathas 06/24/02 Pagell
feet, the excavation should be flattened to a slope ratio of 1 : 1 (horizontal:
vertical) or flatter.
21. It is recommended that no surcharge loads be placed above the temporary
Excavations for a distance equal to the height of the excavation. No surface water
should be permitted to flow over the top of cut.
UBC Seismic Coefficients
22. Groimd Motion - The proposed residence should be designed and constmcted to
resist the effects of seismic ground motions as provided in Section 1626 ofthe
1997 Uniform Building Code. The basis of the design is dependent on and
considers seismic zoning, site characteristics, occupancy configuration, stmctural
system and building height.
23. Soil Profile Type - In accordance with Section 1629.3.1, Table 16-J, and the
underlying geologic conditions a site Soil Profile of Sc is considered appropriate
for the subject property.
24. Seismic Zone - In accordance with Section 1629 and Figure No. 1602, the subject
site is situated within Seismic Zone 4.
25. Seismic Zone Factor (z) - A seismic zone factor of 0.4 is assigned based on
Table 16-1. Since the site is within Seismic Zone 4, Section 1629.4.2 requires a
seismic source type and near-source factor
ProjectNo. 02-1106E7 Mr. James Zathas 06/24/02 Page 12
26. Near-source Factor (Na and Nv) - Based on the known active faults in the region
and distance of the faults from the site, a Seismic Source Type B per Table 16-U,
and Near Source Factor of Na = 1.0 per Table 16-S, and Nv = 1.0 per Table 16-T
are provided.
27. Seismic Coefficients (Ca and Cv) - Using the Soil Profile Type and Seismic Zone
Factor along with Table 16-Q and 16-R, the Seismic Coefficients are Ca = 0.40
and Cv = 0.56.
Preliminary Structural Pavement Section
28. For preliminary design purposes, it is recommended that a stmctural pavement
section of 3 inches of asphaltic concrete over 4 inches of Class II base material
over compacted subgrade be used for the proposed parking and driveway areas.
The upper 8 inches of subgrade and base material should be compacted to at least
95 percent of maximum dry density.
29. The actual stmctural pavement section should be confirmed by "R"-value tests
performed in the subgrade soils after rough grading is completed.
Concrete Flatwork
32. It is recommended that concrete flatwork be a mimmum of 3 V2 inches in
thickness and reinforced with 6x6-10/10 welded wire mesh placed at mid-height
of slab. One inch expansion joints should be provided at 15-foot intervals; with %
ProjectNo. 02-1106E7 Mr. James Zathas 06/24/02 Page 13
inch weakened plane contraction joints at 5-foot intervals.
Backflll In Utility Trenches
33. It is recommended that backfill soils placed in utility trenches located within 5
feet of any improvements and deeper than 12 inches, or backfill placed in any
trench located 5 feet or more from a building and deeper than 5 feet, be
compacted under our observation to at least 90 percent of maximum dry density.
Surface Drainage and Maintenance
34. Adequate drainage control and proper maintenance of all drainage facilities are
imperative to minimize the infiltration of surface water into the underlying soil
mass in order to reduce settlement potential and to minimize erosion. The
building area should have drainage swales which direct storm and excess
irrigation water away from the stmctures and into the street gutters or other
drainage facilities. No surface runoff should be allowed to pond adjacent to the
foundation.
Grading and Foundation Plan Review
35. It is recommended that our firm review the final grading and foundation plans for
the proposed site development to verify their compliance with the Uniform
Building Code, Chapter A33, as required by the State of Califomia.
ProjectNo. 02-1106E7 Mr. James Zathas. 06/24/02 Page 14
LIMTTATION AND UNIFORMTTY OF CONDITIONS
1. The preliminary findings and recommendations contained in this report pertain
only to the site investigated and are based on the assumption that the soil
conditions beneath the entire site do not deviate substantially from those disclosed
in the exploratory trenches. If any variations or undesirable conditions are
encountered during grading, or if the scope of the project differs from that
planned at the present time, our firm should be notified in order that supplemental
recommendations can be presented, if necessary.
2. This report is issued with the understanding that it is the responsibility of the
Owner, or his representative, to ensure that the information and recommendations
presented herein are brought to the attention of the Project Architect and Engineer
and are incorporated into the plans and specifications for the project.
Furthermore, the Owner, or his representative, will also be responsible for taking
the necessary measures to ensure that the Contractor and subcontractors properly
carry out the recommendations in the field.
3. Professional opinions and recommendations presented in this report are based
partly on our evaluation and analysis of the technical information gathered during
the study, partly on the currently available information regarding the proposed
project, and partly on our previous experience with similar soil conditions and
projects of similar scope. Our study has been performed in accordance with the
ProjectNo. 02-1106E7 Mr. James Zathas 06/24/02 Page 15
minimum standards of care exercised by other professional geotechnical
consultants currently practicing in the same locality. We do not, however,
guarantee the performance of the proposed project in any respect, and no
warranties of any kind, expressed or implied, are made or intended in
connection with the study performed by our firm.
4. The findings and recommendations contained in this report are valid as ofthe
present date. However, changes in the conditions of the property could occur
with the passage of time, whether they be due to natural processes or due to man
made actions on the subject and/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 ofthis
report may be invalidated, wholly or partially, by changes outside of our control.
Therefore, this report is subject to review by our firm and should not be relied
upon after a period of two years.
Figure Nos. 1 to 5, inclusive, and Appendices I and II are parts of this report.
SITE LOCATION MAP
PROJECT NO. 02.II06Er FIGURE NO.l
I-
LU LU CC
fe
CC LU Q. z
3
PR0P09ED TOWNhloUSES
T*1
LEGEND
APPRiJXlMATE WCATIOH OF
EXPLO PAT(7RY Ti^ENCH
SCALE r.20'
CARLSBAD BOULEVARD
APPROXIMATE LOCATION OF EXPLORATORY TKENCHE5
PROJECT No. 02. M06E7 RGURE No 2
TRENCH LOG SHEET
TRENCH NO. 1
FT. DESCRIPTION SOIL TYPE
0
1
2
Medium dark brown, very
dry, loose
SAND (SP)
6.4* 99.5-* 82.9%*
3
4
Light brown, damp, medium
dense
SILTY FINE SAND (SM)
7
8
9
10
Light reddish brown, moist,
cemented
FINE SAND (SP)
BOTTOM OF TRENCH (No Refusal)
LEGEND
O
Indicates in-situ density test
Indicates representative sample
ProjectNo. 02-1106E7 Figure No. 3
TRENCH LOG SHEET
TRENCH NO. 2
FT. DESCRIPTION SOIL TYPE
- ^ • 0 Medium brown, very dry, loose SAND (SP)
- . 1
' 2
®dry 7.7* 101.1* 84.2%*
-• 3
4
Light brown, moist,
medium dense to dense
SILTY FINE SAND (SM)
8.1* 109.7* 89.9%*
5
- r
6
Light reddish brown, moist,
medium dense to dense
FINE SAND (SP)
- ^ 7
8
f
9
10
BOTTOM OF TRENCH (No refusal)
Project No. 02-1106E7 Figure No. 4
TRENCH LOG SHEET
TRENCH NO. 3
FT. DESCRIPTION SOIL TYPE
0
1
2
3
4
5
Medium brovra, very dry, loose
dry
Light brown, moist,
medium dense to dense
®
SAND (SP)
SILTY FINE SAND (SM)
BOTTOM OF TRENCH (No refusal)
ProjectNo. 02-1106E7 Figure No. 5
APPENDIX I
GENERAL GRADING AND EARTHWORK SPECIFICATIONS
1.0 General
1.1 These recommended grading and earthwork specifications are
intended to be a part of and to supplement the Geotechnical
Report(s). In the event of a conflict, the recommendations
of the Geotechnical Report(s) will supersede these
specifications. Observations during the course of earthwork
operations may result in additional, new or revised
recommendations that could supersede these specifications
and/or the recommendations in the Geotechnical Report(s).
1.2 The Owner or his authorized representative shall procure -the
services of a qualified Geotechnical Consulting Firm,
hereafter to be referred to as the "Geotechnical
Consultant". (often the same entity that produced the
Geotechnical Report(s).
1.3 The Geotechnical Consultant shall be given a schedule of
work by the Earthwork Contractor for the subject project, so
as to be able to perform required observations, testing and
mapping of work in progress in a timely manner.
1.4 The work herein includes all activities from clearing and
grubbing through fine grading. Included are trenching,
excavation, backfilling, compacting and grading. All work
shall be as shown on the approved project drawings.
1.5 The Geotechnical Consultant or a qualified representative
shall be project on site as required, to observe, map and
document the subsurface exposures so as to verify the
geotechnical desisign suppositions. In the event that
observed conditions are found to be significantly different
from the interpreted conditions during the design.phase, the
Geotechnical Consultant shall notify the Owner, recommend
appropriate changes in design to suit the observed
conditions and notify the agenc(ies) having Jurisdiction,
where required. Subsurface areas to be geotechnically
observed, mapped, record elevations or tested include
cleared natural ground for receiving fill or structures,
"remedial removal" areas, key bottoms and benches.
1.6 The guidelines contained herein and any standard details
attached herewith represent this firm's recommendations for
the grading and all assocaited operations on the subject
project. These guidelines shall be considered to be a part
APPENDIX I Page 2
of these Specifications.
1.7 If interpretation of these guidelines or standard details
result in a dispute(s), the Geotechnical Consultant shall
conclude the appropriate interpretation.
1.8 The Geotechnical Consultant shall observe the processing of
subgrade and fill materials and perform the required
compaction testing. The test results shall be provided to
the Owner and the Contractor and if so required, to the
agenc(ies) having Jurisdication.
1.9 The Geotechnical Consultant shall notprovide "supervision"
or any "direction" of work in progress to the Earthwork
Contractor, or to any of the Contractor's employees or to
any of the Contractor's agents.
1.10 The Earthwork Contractor : The Earthwork Contractor
(Contractor) shall be qualified, experienced, and
knowledgeable in earthwork logistics, preparation and
processing of ground to receive fill, moisture-conditioning
and processing of fill, and compacting fill. The Contractor
shall review and accept the plans, geotechnical report(s),
and these Specifications prior to commencement of grading.
The Contractor shall be solely responsible for performing
the grading in accordance with the plans and specifications.
The Contractor shall prepare and submit to the Owner and the
Geotechnical Consultant a work plan that indicates the
sequence of earthwork grading, the number of "spreads" of
work and the estimated quantities of daily earthwork
contemplated for the site prior to commencement of grading.
The Contractor shall inform the Owner and the Geotechnical
Consultant of changes in work schedules and updates to the
work plan at least 24 hours in advance of such changes so
that appropriate observations and tests can be planned and
accomplished. The Contractor shall not assume that the
Geotechnical Consultant is aware of all grading operations.
The Contractor shall have the sole responsibility to provide
adequate equipment and methods to accomplish the earthwork
in accordance with the applicable grading codes and agency
ordinances, these Specifications, and the recommendations in
the approved geotechnical report(s) and grading plans(s).
If, in the opinion of the Geotechnical Consultant,
unsatisfactory conditions, such as unsuitable soil, improper
APPENDIX I ^^^^ ^
moisture condition. inadequate compaction, i^f^^^^^J^"^
buttress key size, adverse weather, etc., are resulting in a
quality of work less than required in these specifications.
?he Geotechnical Consultant shall reject the work and may
recommend to the owner that cnstruction be stopped until the
conditions are rectified.
2.0 Preparation of Areas to be Filled
2.1 Clearinrand'crubbing" Vegetation, such as brush g^^^
roots, and other deleterious material shall be sufficiently
remov;d and properly disposed of in a method acceptable to
the owner, governing agencies, and the Geotechnical
Consultant.
The Geotechnical Consultant shall evaluate the extent of-
these removals depending on specific si^e conditions. Earth
fill material shall not cental more than 1 percent of
organ" mlierials (by volume). No fill shall cont ain ^^^^^^^
than 5 precent of organic matter. Nesting of the organic
raaterials shall not be allowed.
If Dotentially hazardous materials are encountered, the
contractor shall stop work in the affected area, and a
haSa^dous material specialist shall be informed immediately
Vo^ p?operevIluatlon and handling of these materials prior
to continuing to work in that area.
As oresently defined by the State of California, most
^Ifined petroleum products (gasoline, diesel fuel, motor
oil. greale, coolant, etc.) have chemical constituents that
are considered to be hazardous waste. As such, the
In^iscriminatf dumping or spillage of these fluids onto the
ground may constitute a misdemeanor, punishable by fines
and/or imprisonment, and shall not be allowed.
Materials used for fill, either i«nPorted or o^-^J^^i^^J^J^
not contain hazardous materials as Refined by the California
Code of Regulations, Title 22, Division 4, Chapter dU,
Article 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
Dotential presence of hazardous materials. However, ir
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
APPENDIX I Page 4
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.
2.2 Any asphaltic 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.
2.3 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 immeidately to evaluate the significance of the
unanticipated condition.
2.4 Processing : Existing ground that has been declared
satisfactory for support of fill by the Geotechnical
Consultant shall be scarified to a minimum depth of 6
inches. Existing ground that is not satisfactory shall be
overexcavated as specified in the following section.
Scarification shall continue until soils are broken down and
free of large clay lumps or clods and the working surface is
reasonably uniform, flat, and free of uneven features that
would inhibit uniform compaction.
2.5 Overexcavation : In addition to removals and overexcavations
recomended in the approved geotechnical report (s) and the
grading plan, soft, loose, dry, saturated, spongy, organic-
rich highly fractured or otherwise unsuitable ground shall
be overexcavated to competent ground as evaluated by the
Geotechnical Consultant during grading.
2.6 Benching : Where fills are to be placed on ground with
slopes steeper than 5 : 1 (horizontal : vertical), the
ground shall be stepped or benched. Please see the Standard
Details for a graphic illustration. The lowest bench or key
shall be a minimum of 15 feet wide and at least 2 feet deep,
into competent material as evaluated by the Geotechnical
Consultant. Other benches shall be excavated a minimum
height of 4 feet into competent material or as otherwise
recommended by the Geotechnical Consultant. Fill placed on
ground sloping flatter than 5 : 1 shall also be benched or
otherwise overexcavated to provide a flat subgrade for the
fill.
APPENDIX I Page 5
2.7 Evaluation/Acceptance of Fill Areas : All areas to receive
fill, including removal and processed areas, key bottoms,
and benches, shall be observed, mapped, elevations recorded,
and/or tested prior to being accepted by the Geotechnical
Consultant as suitable to receive fill. the contractor
shall obtain a written acceptance from the Geotechnical
Consultant prior to fill placement. A licensed surveyor
shall provide the survey control for determining elevations
of processed areas, keys, and benches.
3.0 Fill Material
3.1 General : Material to be used as fill shall be essentially
free of organic matter and other deleterious substances
evaluated and accepted by the Geotechnical Consultant prior
to placement. Soils of poor quality, such as those with
unacceptable gradation, high expansion potential, or low
strenght shall be placed in areas acceptable to the
Geotechnical Consultant or mixed with other soils to achieve
satisfactory fill raaterial.
3.2 Oversize : Oversize material defined as rock, or other
irreducible material with a maximum dimension greater than 8
inches shall not be buried or placed in fill unless
location, materials and placement methods are specifically
accepted by the Geotechnical Consultant. Placement
operations shall be such that nesting of oversized material
does not occur and such that oversize material is competely
surrounded by compacted or densified fill. Oversize
material shall not be placed within 10 vertical feet of
finish grade or within 2 feet of future utilities or
underground construction.
3.3 Import : If importing of fill material is required for
grading, proposed import material shall meet the
requirements of Section 3.1. The potential Import source
shall be given to the Geotechnical Consultant at least 48
hours (2 working days) before importing begins so that its
suitability can be determined and appropriate tests
performed.
4.0 Fill Placement and Compaction
4.1 Fill Layer : Approved fill material shall be placed in areas
prepared to receive fill (per Section 3.0) in near-
APPENDIX I Page 6
horizontal layers not exceeding 8 inches in loose thickness.
The Geotechnical Consultant may accept thicker layers if
testing indicates the grading procedures can adequately
compact the thicker layers. Each layer shall be spread
evenly and mixed thoroughly to attain relative uniformity of
material and moisture throughout.
4.2 Fill Moisture Conditioning : Fill soils shall be watered,
dried back, blended, and/or mixed, as necessary to attain a
relatively uniform moisture content at or slightly over
optimum. Maximum density and optimum soil moisture content
tests shall be performed in accordance with the American
Society of Testing and Materials (ASTM Test Method D1557-
91) .
4.3 Compaction of Fill : After each layer has been moisture-
conditioned, mixed, and evenly spread, it shall be uniformly
compacted to not less than 90 percent of maximum dry density
(ASTM Test Method D1557-91). Compaction equipmnt shall be
adequately sized and be either specifically designed for
soil compaction or of proven reliability to efficiently
achieve the specified level of compaction with uniformity.
4.4 Compaction of Fill Slopes : In addition to normal compaction
procedures specified above, compaction of slopes shall be
accomplished by backrolling of slopes with sheepsfoot
rollers at increments of 3 to 4 feet in fill elevation, or
by other raethods producing satisfactory results acceptable
to the Geotechnical Consultant. Upon completion of grading,
relative compaction of the fill, out to the slope face,
shall be at least 90 percent of maxiraum dry density per ASTM
Test Method D1557-91.
4.5 Compaction Testing : Field tests for moisture content and
relative corapaction of the fill soils shall be performed by
the Geotechnical Consultant. Location and frequency of
tests shall be at the Consultant's discretion based on field
conditions encountered. Compaction test locations will not
necessarily be selected on a random basis. Test locations
shall be selected to verify adequacy of compaction levels in
areas that are Judged to be prone to inadequate compaction
(such as close to slope faces and at the fill/bedrock
benches).
4.6 Frequency of Compaction Testiing : Tests shall be taken at
intervals not exceeding 2 feet in vertical rise and/or 1,000
cubic yards of compacted fill soils embankment. In
APPENDIX I Page 7
addition, as a guideline, at least one test shall be taken
on slope faces for each 5,000 square feet of slope face
and/or each 10 feet of vertical height of slope. The
Contractor shall assure that fill construction is such that
the testing schedule can be accomplished by the Geotechical
Consultant. The Contractor shall stop or slow down the
earthwork construction if these minimum standards are not
met.
4.7 Compaction Test Locations : The Geotechnical Consultant
shall document the approximate elevation and horizontal
coordinates of each test location. The Contractor shall
coordinate with the project surveyor to assure that
sufficient grade stakes are established so tha^t the
Geotechnical Consultant can determine the test locations
with sufficient accuracy. At a minimum, two grade stakes
within a horizontal distance of 100 feet and vertically less
than 5 feet apart from potential test locations shall be
provided.
5.0 Subdrain Installation
Subdrain systems shall be installed in accordance with the
approved geotechiucal report(s). the grading plan, and the
Standard Details, The Geotechnical Consultant may recommend
additional subdrains and/or changes in subdrain extent,
location. grade, or material depending on conditions
encountered during grading. All subdrains shall be surveyed
by a land surveyor/civil engineer for line and grade after
installation and prior to burial. Sufficient tirae should be
allowed by the Contractor for these surveys.
6.0 Excavation
Excavations, as well as over-excavation for remedial
purposes, shall be evaluated by the Geotechnical Consultant
during grading. Remedial removal depths shown on
geotechnical plans are estimates only. The actual extent of
removal shall be determined by the Geotechnical Consultant
based on the field evaluation of exposed conditions during
grading. Where fill-over-cut slopes are to be graded, the
cut portion of the slopes shall be made, evaluated, and
accepted by the Geotechnical Consultant prior to placement
of materials for construction of the fill portion of the
slope, unless otherwise recommended by the Geotechnical
Consultant.
APPENDIX I Page 8
7.0 Trench Backfill
7.1 The Contractor shall follow all OSHA and Cal/OSHA
requirements for safety of trench excavations.
7.2 All bedding and backfill of utility trenches shall be done
in accordance with the applicable provisions of Standard
Specifications of Public Works Construction. Bedding,
material shall have a Sand Equivalent greater than 30
(SE>30). The bedding shall be placed to 1 foot over the top
of the conduit and densified by Jetting. Backfill shall be
placed and densified to a rainiraura of 90 percent of raaximum
from 1 foot above the top of the conduit to the surface.
7.3 The Jetting of the bedding around the conduits shall be
observed by the Geotechnical Consultant.
7.4 The Geotechnical Consultant shall test the trench backfill
for relative compaction. At least one test should be raade
for every 300 feet of trench and 2 feet of fill.
7 5 Lift thickness of trench backfill shall not exceed those
allowed in the Standard Specifications of Public Works
Construction unless the Contractor can demonstrate to the
Geotechnical Consultant that the fill lift can be compacted
to the rainiraum relative compaction by his alternative
equipment and method.
Pf>OJ€CTCD PU>K
1 TO \ LUXUUU FfCiJ TCe
eu:« TO A^s>fCveD oacow
oncuwo
r uw.
,—w UIH.—
L0V<Ti5T W>*C« (KE^
FILL SLOPE
-3^ REWOVS
KATUaiX OROOHO
„^WW
FILL-OVER-CUT
SLOPE
lUTEJtiXL
— UlK.
TO Fll p<-«^cews<r TO A56<;Fe AceiuATe oecocow cc^<xTO«3
CUT
TO M ccwrmuoTH) Pf*c«
TOPUPL'.Cam'v ^
OHOyKO
PflOJCCTCD PO-Ht
1 TO I uAXwuu rroJ
TCC Cf etX5Pe TO
CUTOVER-PILL
SLOPE
RCUOVTC
Fof Subdrains S«e
Standard Detail C
'WTtTj -DEKCH HEWHT
X* UlK,
KEYOtPTH kowtrrtcKcH
KEYING AND BENCHING
DETAIL. A ALLIED EARTH
TECHNOLOGY
FINISH QRADB
SLOPE
FACE
ED OR FLOODED
GRANULAR WATE RIAL
• Oversize rock is larger rhan 8 inches
;.n largest dimension.
• Excavate a trench in the compacted
fill deep enough to bury ail thc rock.
• Backflll wilh granular soil Jcned or
flooded in place to fill all thc voids.
• Do not bury rock within 10 feet of
finish grade.
Windrow of buried rock shall be
parallel to the finished slope fil
JETTED OR FLOODED
GRANULAR WATERLAL
OVERSIZE ROCK DISPOSAL
DERAIL- B ALLIED EARTH
TECHNOLOGY
NATURAL
GROUND
BENCHING
REMOVE
UNSUITABLE
MATERIAL
\
WIN. OVERLAP FROM T>iE TOP
HOG RING TIED EVERY « FEET
CALTRANS CUSS II ^
PERMEABLE OR rz ROCK' \ -
(9FT.'/FT.) WRAPPED IN \^
A
FIL-reR FABRIC
FILTEH FABRIC , .
ffivln """SCOOECTOR PIPE 5HAJJ.
CANYON SUBDRAIN OUTLET DETAIL PlP|-^H||T»^HTAiLO
DESIGN
• FINISHED
GRADE
PERFORATED PIPE
MIN.
10- MiN. BACKFILL
i
FILTER FABRIC
(WIRA>1140 0R
APPROVED
EOUr/ALEKT)
20' UIN.-
,NON-PEKFORATED.
WiN.
5' MIN. i« ROCK VmAPPED IN FILTER
'FABRIC OR CALTRANS CLASS II
PERMEABLE
CANYON SUBDRAINS
DETAiL. C ALLIED EARTH
TECHNOLOGY
OUTLET PIPES
4'<|. NON-PERFORATED PIPE,
100* MAX O.c. HORIZONTALLY,
30' MAX O.C. VERTICALLY
POSmVE SEAL
SHOULD BE
PROVIDED AT
THE JO
12* MIN. OVERLAP FROM T>^E TOP
'HOQ'RING TIED EVERY 6 FEET
FABRIC
(HIRAP1140 OR
APPROVED
EQUIVALEKT)
/ T-OONNEOnON..FOR
COLLECTOR PIPE TO
OLTTLETPIPE
OUTLET PIPE
(NON-PERFORATED)
CALTRANS CLASS II
PERMEABLE OR « ROCK
(JFT.'/FT,) YiWPED IN
FILTER FABRJC
SUBDRAIN INSTALLATION_ Subdrain coilector pipe shall be Installed with perforatious
down or, unless otherwise designated by the geotechnical consultant Outlet pipe shall-be
non- perforated pipe. The subdrain pipe shall have at least 8 perforatipns uniformly
spaced per foot. Perforation shall be l/4"to 1/2" if driUed holes arcrused. AU subdrain
pif>cs shall have a gradient at least 2% towards the outlet.
SUBDRAIN PIPE_ Subdrain pipe shall be ASTM D2751, SDR 23.5 or ASTM D 1527,
Schedule 40, or ASTM D3034, SDR 23.5, Schedule 40 Polyvinyl Chloride Plastic (PVC) pip«-
All outlet pipe shall be placed in a trench no wider than twice the subdrain pipe. Pipe shall be
in soil Of SE > 30 jetted or flooded in place except for the outside 5 feet which shall be
native soil backfill.
BUTRESS OR REPLACEMEMI HLL
SUBDRAINS
DETAIL -D ALLIED EARTH
TECHNOLOGY
Project No. 02-1106E7 James Zathas 06/24/02
APPENDIX II
Laboratory Test Results
The maximum dry densities and optimum moisture contents of the fill soils
encountered, as determined in accordance v^th A.S.T.M. D1557, Method A, are
presented as follows:
Soil
Description
Maximum Optimum Moisture
Dry Density Content
(lbs./cu.ft.) (% Dry Wt)
Trench #1
Sample #1
Depth 2.0'
Medium dark brown
fme sand (SP)
120.0 11.0
Trench #1
Sample #2
Depth 4.0'
Light brown silty fine
sand (SM)
122.0 10.5
The Expansion Index of the most clayey soils was determined in accordance with
UBC Test No. 18-2. The results ofthe test are presented as follows :
Sample
Condition
Initial M.C. (%)
Initial Density (pcf)
Final M.C. (%)
Normal Stress (psf)
Expansion Index
Tl-Bl @2.0'
Remolded
10.9
108.1
21.9
144.7
25*
* Considered to possess LOW expansion potential