HomeMy WebLinkAboutSDP 98-23; CARLSBAD PACIFIC CENTER PHASE 3; REPORT OF PRELIMINARY GEOTECHNICAL INVESTIGATION; 2000-06-21w
CHRJSTIAN WHEELER. ENGINEER.ING
REPORT OF PRELIMINARY GEOTECHNICAL INVESTIGATION
PROPOSED CARLSBAD PACIFIC CENTER PHASE III OFFICE BUILDING
705 PALOMAR AIRPORT ROAD
CARLSBAD, CALIFORNIA
PREPARED FOR:
PRENTISS PROPERTIES
c/o SMITH CONSULTING ARCHITECTS
5355 MIRA SORRENTO PLACE, SUITE 750
SAN DIEGO, CALIFORNIA 92121
PREPARED BY:
CHRISTIAN WHEELER ENGINEERING
4925 MERCURY STREET
SAN DIEGO, CALIFORNIA 92111
4925 Mercury Street .. San Diego, CA 92111 ... 858-496-9760 .. FAX 858-496-9758
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June 21,2000
Prentiss Properties
c/o Smith Consulting Architects
5355 Mira Sorrento Place, Suite 750
San Diego, California 92121
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CHRJSTIAN WHEELER. ENGINEER-ING
CWE 200.298.1
SUBJECT: REPORT OF PRELIMINARY GEOTECHNICAL INVESTIGATION,
PROPOSED CARLSBAD PACIFIC CENTER PHASE III OFFICE BUILDING,
705 PALOMAR AIRPORT ROAD, CARLSBAD, CALIFORNIA.
Ladies and Gentlemen:
In accordance with your request, we have completed a geotechnical investigation for the subject
development. We are presenting herewith a report of our finding and recommendations.
In general, we found the subject property suitable for the proposed construction, provided the
recommendations provided in this report are followed. The most significant geotechnical conditions
affecting the proposed development are the presence of relatively loose, clayey fill material in the area of the
proposed office building pad and saturated soils in the proposed west parking lot axea. The fill material in the
proposed office building area, which varied in depth from two to eight feet, is considered to be of relatively
low strength and moderately expansive. This material is considered unsuitable in its current condition to
support settlement-sensitive improvements. As such, it is recommended that all the fill material in the
proposed building pad area be removed and replaced as properly compacted structural fill. Due to the
moderate expansive potential of the fill material, special foundation and on-grade slab design will be required.
Specific recommendations regaxding these conditions are presented in the attached report. In the area of the
proposed west parking lot, the saturated soils will need to be removed, moisture conditioned and replaced a$
properly compacted fill.
4925 Mercury Street ... San Diego, CA 92111 .. 858-496-9760 ... FAX 858-496-9758
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CWE 200.298.1 June 21, 2000 Page No. 2
If you have any questions after reviewing this report, please do not hesitate to contact our office. This
opportunity to be of professional service is sincerely appreciated.
Respectfully submitted,
CHRISTIAN WHEELER ENGINEERING
Charlie Carter, Staff Engineer
Charles H. Christian, RGE # 00215
CHC:CRB:cgc
cc: (2) Submitted
(3) Smith Consulting Architects
(1) Prime Structural Engineers
Curtis R. Burdett, CEG # 1090
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TABLE OF CONTENTS
PAGE
Introduction and Project Description .............................................................................................................. 1
Project Scope ........................................................................................................................................................ 1
Findings .................................................................................................................................................................. 3
Site Description ......................................................................................................................................... , ... 3
General Geology and Subsurface Conditions ...... : .................................................................................... 3
Geologic Setting and Soil Description .................................................................................................. 3
Fill ............................................................... ; ........................................................................................ 3
Topsoil ................................................................................................................................................ 4
Weathered Terrace Deposits ....................................................................... ; ................................... 4
Terrace Deposits ............................................................................................................................... 4
Groundwater ............................................................................................................................................. 4
Tectonic Setting ........................................................................................................................................ 5·
Geologic Hazards ......................................................................................................................................... 5
General. ...................................................................................................................................................... 5
Ground Shaking ....................................................................................................................................... 5
Seismic Design Parameters ..................................................................................................................... 6
Landslide Potential and Slope Stability ................................................................................................. 7
Liquefaction .............................................................................................................................................. 7
Flooding ..................................................................................................................................................... 7
Tsunamis ................................................................................................................................................... 7
Seiches ........................................................................................................................... : ............................ 7
Conclusions ........................................................................................................................................................... 7
Recommendations .................................................................................... : .......................................................... 8
Grading and Earthwork ............................................................................................................................... 8
Observation of Grading .......................................................................................................................... 8
Clearing and Grubbing ............................................................................................................................ 8
Site Preparation ........................................................................................................................................ 8
Temporary Cut Slopes ............................................................................................................................. 8
Processing of Fill Areas ........................................................................................................................... 9
Compaction and Method of Filling .................................................................................... : .. , .............. ; 9
Surface Drainage ...................................................................................................................................... 9
Grading Plan Review ............................................................................................................................. 10
Foundation Recommendations ................................................................................................................ 10
General. .................................................................................................................................................... 1.0
Bearing Capacity ..................................................................................................................................... 10
Footing Reinforcing ................................................................................................................ ,' .............. 10
Lateral Load Resistance ......................................................................................................................... 10
Foundation Excavation Observation .................................................................................................. 11
On-Grade Slabs .......................................................................................................................................... 11
Interior Floor Slabs ................................................................................................................................ 11
Moisture Protection for Interior Slabs ............................................................................................... 11
Exterior Concrete Flatwork .................................................................................................................. 11
Preliminary Pavement Sections ................................................................................................................ 11
Traffic Index ........................................................................................................................................... 11
R-Value Test ........................................................................................................................................... 12
Preliminary Structural Section ................................................................................................ : ............. 12
CWE200.298
Proposed Carlsbad Pacific Center III
705 Palomar Airport Road
Carlsbad, California
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Limitations .......................................................................................................................................................... 12
Review, Observation and Testing ............................................................................................................ 12
Uniformity of Conditions .......................................................................................................................... 13
Change in Scope ......................................................................................................................................... 13
Time Litnitations ......................................................................................................................................... 13
Professional Standard ................................................................................................................................. 13
Client's Responsibility ................................................................................................................................ 14
Field Explorations .............................................................................................................................................. 14
Laboratory Testing .................................. 7 .......................................................................................................... 15
TABLES
Table I
Table II
FIGURES
Figure 1
PLATES
Plate 1
Plates 2-8
Plates 9-10
Plate 11
Plate 12
APPENDICES
Appendix A
AppendixB
ATTACHMENTS
Maximum Bedrock Accelerations, Page 6
Seismic Design Parameters, Page 6
Site Vicinity Map, Follows Page 1
Site Plan
Boring Logs
Test Pit Logs
Laboratory Test Results
R-Value Test Results
References, Topographic Maps, and Aerial Photographs
Recommended Grading Specifications -General Provisions
CWE 200.298
Proposed Carlsbad Pa~ific Center III
705 Palomar Aitport Road
Carlsbad, California
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PRELIMINARY GEOTECHNICAL INVESTIGATION
PROPOSED CARLSBAD PACIFIC CENTER PHASE III OFFICE BUIIDING
705 PALOMAR AIRPORT ROAD
CARLSBAD, CALIFORNIA
INTRODUCTION AND PROJECT DESCRIPTION
This report presents the results of a preliminary geotechnical investigation performed for the proposed Carlsbad
Pacific Center Phase III Office Building, to be constructed at 705 Palomar Airport Road in Carlsbad, California.
Figure Number 1 presented on the following page provides a vicinity map showing the location of the property.
The proposed office building will be the third three-story office building const:rUcted on the property. We
understand the building will be a steel-frame structure with conventional spread footings and an on;.grade
concrete floor slab. In addition to the office building, two areas of additional parking, one in the southeast
comer of the property and one in the western portion of the subject property will be constructed Pre~e
grading is anticipated to consist of cuts and fills ofless than five feet from the existing site grades.
To aid in the preparation of this report, a Site Plan prepared by Smith Consulting Architects, whjch shows the
proposed configuration of the site with the location and configuration of the proposed building, was-
provided to us. A copy of this plan was used as the base map for our Site Plan and is included herewith as
Plate Number 1.
This report has been prepared for the exclusive use of Prentiss Properties and their design consultants for
specific application to the project described herein. Should the project be changed in any way, the modified
plans should be submitted to Christian Wheeler Engineering for review to determine their conformance with
our recommendations and to determine if any additional subsurface investigation, laboratory testing and/or
recommendations are necessary. Our professional services have been performed, our findings obtained and our
recommendations prepared in accordance with generally accepted engineering principles and practices. this
warranty is in lieu of all other warranties, express or implied.
PROJECT SCOPE
The scope of our preliminary investigation included: surface reconnaissance; subsurface ex;ploration; obtaining
representative soil samples; laboratory testing; analysis. of the field and laboratory data; research of available
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Figure No.1
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CWE200.298 June 21, 2000 Page No. 2
geological literature pertinent to the site; and preparation of this report. More specifically, the intent of this
analysis was to:
a) Explore the subsurface conditions of the site to the depths influenced by the proposed
cons truction;
b)
c)
d)
e)
f)
g)
h)
Evaluate, by laboratory tests, the engineering properties of the various strata that may influence the
proposed development, including soil bearing capacities, expansive characteristics and settlelDep.t
potential;
Describe the general geology at the site including possible geologic hazards that coulq have an
effect on the site development, and provide the seismic design parameters as required by the most
recent edition of the Uniform Building Code;
Address potential construction difficulties that may be encountered due to soil conditions,
groundwater or geologic hazards, and provide recommendations concerning these problems;
Develop soil engineering criteria for the site preparation and grading, and provide design
information regarding the stability of cut and fill slopes;
Recommend an appropriate foundation system for the type of structure anticipated and develop
soil engineering design criteria for the recommended foundation design;
Provide preliminary recommendations for structural pavement sections of asphalt concrete
pavement and Portland Cement concrete; and
Present our opinions in a written report, that includes, in addition to ooc findings and
recommendations, a site plan showing the location of our subsurface explorations, exploration logs
and a summary of our laboratory test results.
It is not within the scope of our services to perform laboratory tests' to evaluate the chemical characteristics
of the on-site soils in regard to their potentially corrosive impact to on-grade concrete and below grade
improvements. If desired, we can obtain samples of representative soils and submit them to a chemical
laboratory for analysis. We suggest that such samples be obtained after grading is complete and the soils that
can affect concrete and other improvements are in place. Further, it should be understood Christian Wheeler
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CWE200.298 June 21, 2000 Page No. 3
Engineering does not practice corrosion engineering. If such an analysis is necessary, we recommend that the
developer retain an engineering firm that specializes in this field to consult with them on this matter.
FINDINGS
SITE DESCRIPTION
The subject site is a relatively level, irregular-shaped parcel that presendy supports two three-story office
buildings and associated parking, driveways and landscaped areas. Based on referenced topographical maps,
the site elevation appears to be approximately 55 feet above Mean Sea Level. Access onto the property is via
Avenida Encinas, which is the west boundary of the site. Palomar Airport Road borders the north and east
sides of the subject property, and developed commercial properties border the south and northwest sides. of
the site.
The portion of the site proposed for the new office building is eurrendy a mounded landscaped area with
grass that is bordered by hardscape and sidewalks to the north and west and paved parking and driveways to
the south and east. A masonry block trash enclosure is located on the area's east side and one of the two
current three-story office buildings is situated adjacent to the west boundary sidewalk. The proposed paved
parking area on the site's southeast side is currendy undeveloped with light grass on the surface. The
proposed paved parking area on the site's west side is currendy landscaped with grass and tress along its'
perimeter.
GENERAL GEOLOGY AND SUBSURFACE CONDITIONS
GEOLOGIC SETTING AND SOIL DESCRIPTION: The subject site is located along the western edge of
the Coastal Plains Physiographic Province of San Diego County. Based upon the results of our limited
e.'q)loration and analysis of readily available, pertinent geologic and geotechnical literature, the site appears to be
predominandy underlain by Quaternary-age terrace deposits, which are manded by fill material, topsoil, and
weathered terrace deposits. These materials are described below:
FILL (Qat): Fill material was encountered in Test Borings B-4, B-5, B-6, B-7, and Test Pits P-l andP~2.
This material was found to extend to depths ranging from about 2 to 8 feet below the existing ground
surface in the proposed office building area and approximately 2V2 to 4 feet below the ground surface in
the proposed west side parking area. The fill material encountered in the proposed office building area
was noted to generally consist of medium brown, dark brown, and gray, clayey sand eSC) and sandy clay
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C\VE 200.298 June 21, 2000 Page No. 4
(CL) that was observed to be generally wet to saturated and soft/loose to medium dense in consistency.
The fill material found in the proposed west parking area was noted to generally consist of medium
brown, greenish-brown, orangish-brown, and reddish-brown, fine-to medium-grained, clayey sand (SC)
and sandy clay (CL). 1his fill material was observed to be generally wet to saturated and graded from
loose/ soft to medium dense/ medium stiff to dense in consistency as depths increased
TOPSOIL: Topsoil was encountered in B-1 and B-2 at the surface and extended to depths ranging
from approximately six inches to one foot below the existing site grade. The topsoil materiaI'was noted
, '
to generally consist of light brown and medium brown, fine-to medium-grained, silty sand (SM). This
material was observed to be generally dry and loose in consistency.
WEATHERED TERRACE DEPOSITS (Qt): Weathered Quaternary-age terrace deposits were
found in Test Borings B-2, B-4, and B-7. This weathered layer was found to be approximately three feet
thick. The weathered terrace deposits were observed to generally consist of medium brown, sandy clay
(CL) and were noted to be generally moist and stiff to very stiff in consistency.
TERRACE DEPOSITS (Qt): Quaternary-age terrace deposits were encountered in each of our
subsurface explorations at depths ranging from approximately one foot to eleven feet below tl:e existing
ground surface and extended to depths greater than our maximum explored depth of 20 feet below the
current site grade. These deposits were observed to generally consist of light brown, medium brown,
orangish-brown, gray, and dark reddish-brown, fine-to medium-grained clayey sand (SC), sandy clay
eCL), and poorly-graded sand (SP). The granular portions of the terrace deposits were noted to be
generally moist and medium dense to very dense in consistency. The clayey portions were observed to
be generally moist and stiff to very stiff in consistency.
Based upon visual observation of the encountered soils and laboratory testing, the fill material, tops<;>il. and
terrace deposits are anticipated to possess a "low" to "moderate" expansion potential (based upon UBC Test
Method 18-2).
GROUNDWATER: No groundwater was encountered in our subsurface explorations; however, it should be
noted that the soil material encountered at shallow depths in the prop,osed west parking area and office building
area was very wet and saturated. The proposed west parking area was found to be inaccessible with our truck-
mounted drill rig due to the saturated surface conditions. These saturated conditions are most likely the result of
landscape irrigation and not from groundwater seepage. It should be recognized that minor groundwater seepage
problems might occur after development of a site even where none were present before development These are
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CWE200.298 June 21,2000 Page No. 5
usually minor phenomena and are often the result of an alteration in drainage patterns and! or an increase in
irrigation water. Based on the permeability characteristics of the soil and the anticipated usage and development,
it is our opinion that any seepage problems which will be minor in extent. These potential "nujsance" problems
can be mitigated by the use of proper landscaping techniques.
TECTONIC SETTING: No major faults are known to traverse the subject site but it should be noted that
much of South em California, including the San Diego County area, is characterized by a series of Quaternary-
age fault zones which typically consist of several individual en echelon faults that generally strike in a
northerly to north-westerly direction. Some of these fault zones (and the individual faults within the zones).
are classified as active while others are classified as only potentially active, according to the criteria of the
California Division of Mines and Geology. Active fault zones are those which have shown conclusive
evidence of faulting during the Holocene Epoch (the most recent 11,000 years) while potentially active fault
zones have demonstrated movement during the Pleistocene Epoch (11,000 to 1.6 million years before the
present) but no movement during Holocene time.
A review of available geologic maps indicates that a portion of the Rose Canyon Fault Zone is located.
approximately 3.7 miles west of the site. Other active fault zones in the region that could possibly affect the
site include the Coronado Bank, San Diego Trough, and San Clemente Fault Zones to the southwest and the
Elsinore, San Jacinto, and San Andreas Fault Zones to the northeast.
GEOLOGIC HAZARDS
GENERAL: No geologic hazards of sufficient magnitude to preclude development of the site as we presendy
contemplate it are known to exist. In our professional opinion and to the best of oW: knowledge, the site is .
suitable for the proposed construction.
GROUND SHAKING: A likely geologic hazard to affect the site is ground shaking as result of movement
along one of the major active fault zones mentioned above. The maximum bedrock accelerations that would be
attributed to a maximum magnitude earthquake occurring along the nearest fault segments of selected fault zones .
that could affect the site are summarized in the following Table I.
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CWE200.298 June 21, 2000 Page No. 6
TABLE I
Fault Zone Distance Maximum Magnitude Maximum Bedrock
Earthquake Acceleration
Rose Canyon 3.7 miles 6.9 magnitude 0.45g
Coronado Bank 22 miles 7.4 magnitude 0.18g
Elsinore 25 miles 7.1 magnitude 0.12g
San Diego Trough 30 miles 7.3 magnitude 0.12g
San Jacinto 48 miles 7.2 magnitude 0.07 g
San Clemente 56 miles 7.3 magnitude 0.06g
Probable ground shaking levels at the site could range from slight to moderate, depending on such factors as
the magnitude of the seismic event and the distance to the epicenter. It is likely that the site will experience
the effects of at least one moderate to large earthquake during the life of the proposed improvements.
SEISMIC DESIGN PARAMETERS: Based on a maximum magnitude (Mmax) earthquake of 6.9 along
the nearest portion of the Rose Canyon Fault Zone, the Maximum Bedrock Acceleration at the site would be
approximately 0.45 g. For structural design purposes, a damping ratio not greater than 5percel;1t of criticaJ.
dampening, and Soil Profile Type SD are recommended (UBC Table 16-J). Based upon the location of the
site being approximately six kilometers from the Rose Canyon Fault (Type B Fault), Near Source Factors Na
equal to 1.0 and Nv equal to 1.16 are also applicable. These values, along with other seispUcaUy related design
parameters from the Uniform Building Code CUBC) 1997 edition, Volume II, Chapter 16, utilizing a Seismic
Zone 4 are presented in tabular form below.
TABLE II
UBC -Chapter 16 Seismic Recommended " ,
Table No. Parameter Value
16-1 Seismic Zone Factor Z 0.40
16-J Soil Profile Type SD
16-Q Seismic Coefficient Ca O.44Na
16-R Seismic Coefficient Cv 0.64Nv
16-S Near Source Factor Na 1.0
16-T Near Source Factor Nv 1.16
16-U Seismic Source Type B
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C\VE 200.298 June 21, 2000 Page No. 7
LANDSLIDE POTENTIAL AND SLOPE STABILITY: A detailed, deterministic slope stability analysis.
was not included within our scope of services. Based on our experience within the vicinity of the. site and .the
absence of significant existing or proposed slopes within or adjacent to the site, it is our opinion that the risk
of deep-seated slope instability problems can be considered to be low.
LIQUEFACTION: The near-surface soils encountered at the site are not considered susceptible to liquefaction
due to such factors as soil density, grain-size distribution and the absence of shallow groufi(~water conditions.
FLOODING: The site is located outside the boundaries of both the lOO-year and the SOD-year floodplains.
according to the maps prepared by the Federal Emergency Management Agency.
TSUNAMIS: Tsunamis are great sea waves produced by submarine earthquakes or volcanic eruptions. Due to
the location of the site, it should not be affected by a tsunami.
SEICHES: Seiches are periodic oscillations in large bodies of water such as lakes, harbors, bays or reservoirs.
Due to the site's location, it will not be affected by seiches.
CONCLUSIONS
In general, we found the subject property suitable for the proposed construction, provided the
recommendations provided herein are followed. The most significant geotechnical conditions. affecting the
proposed development are the presence of relatively loose, clayey fill material in the area of the proposed
building pad and saturated fill soils in the area of the new west parking lot. The fill niaterial·in the proposed
building pad area, which varied in depth from two to eight feet, is considered to be of relatively low strength
and moderately expansive. This material is considered unsuitable in its a,u:rent condition to support
settlement-sensitive improvements. As such, it is recommended that all the fill material in the proposed
building pad area be removed and replaced as properly compacted structural fill In addition, the saturated
soils in the proposed west parking area will need to be removed, moisture conditioned, and replaced as
properly compacted fill.
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CWE200.298 June 21, 2000 Page No. 8
RECOMMENDATIONS
GRADING AND EARTHWORK
OBSERVATION OF GRADING: Continuous observation by the Geotechnical Consultant is essential
during the grading operation to confirm conditions anticipated by our investigation, to allow adjustments in
design criteria to reflect actual field conditions exposed, and to determine that the grading proceeds in general
accordance with the recommendations contained herein.
CLEARING AND GRUBBING: Site preparation should begin with the removal from the proposed
improvement areas of all existing structures, foundations, slabs, pavements, and above grade and
underground utilities. In addition, all vegetation and other deleterious materials should be removed from the
portions of site that will receive improvements. Ths should include all root balls from trees in the landscaped
areas and all significant root material. The resulting organic materials and construction debris should be
disposed of in an appropriate off-site facility.
SITE PREPARATION: After clearing and grubbing, all disturbed soil and fill material within the proposed
building pad area, paved areas and any other areas that will support settlement-sensitive improyements should
be removed. These removals are anticipated to extend approximately two to eight feet below the current
ground surfaces in the proposed office building pad area. All saturated soils within the proposed west
parking area should also be removed. Removals in the west parking lot area are anticipated to be up to about
four feet below the current ground surface. Based upon the observations of our field representative, localized
deeper removals may be required. The removed fill materials may be stockpiled for reuse on the site as
structural fill material. Where possible, the grading area shall extend a minimum of five feet horizontally
beyond the boundaries of the proposed building pad area.
TEMPORARY CUT SLOPES: Temporary cut slopes of up to about eight feet in height are anticipated to
be required during the recommended site preparation. Temporary cut slopes of up to eight feet in· height can
be excavated at inclinations of 0.5 to 1.0 (horizontal to verticaD or flatter. All temporary cut slopes should be
observed by the engineering geologist during grading to ascertain that no unforeseen adverse conditions exist
No surcharge loads such as soil or equipment stockpiles, vehicles, etc. should be allowed within a distance
from the top of temporary slopes equal to half the slope height.
The contractor is solely responsible for designing and constructing stable, temporary excavations and may
need to shore, slope, or bench the sides of trench excavations as required to maintain the stability of the
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C\VE 200.298 June 21, 2000 Page No. 9
excavation sides. The contractor's "responsible person", as defined in the OSHA Construction Standards
for Excavations, 29 CFR, Part 1926, should evaluate the soil exposed in the excavations as part of the
con tractor's safety process. Temporary cut slopes should be constructed in accordance with the
recommendations presented in this section. In no other case should slope height, slope inclination, or
excavation depth, including utility trench excavation depth, exceed those specified in local, state, and federal
safety regulations.
PROCESSING OF FILLAREAS: Prior to placing any new fill soils or constructing any new improvements
in areas that have been cleaned out to receive fill and have been approved by the geotechnical consultant or his
representative, the exposed soils should be scarified to a depth of 12 inches, moisture conditioned, and
compacted to at least 90 percent relative compaction.
COMPACI'ION AND METHOD OF FILLING: All structural fill placed at the site should be
compacted to a relative compaction of at least 90 percent of maximum dry density as determined by ASTM
Laboratory Test D1557. Fills should be placed at or slighdy above optimum moisture content, in lifts six to
eight inches thick, with each lift compacted by mechanical means. Fills should consist of approved earth
material, free of trash or debris, roots, vegetation, or other materials determined to be unsuitable by our soil
technicians or project geologist. Fill material should be free of rocks or lumps of soil in excess of six inches
in maximum dimension. Based upon the results of our sub-surface exploratiort and laboratory testing most
of the on-site soils appear suitable for use as ftIl material.
All utility trenches should be compacted to a minimum of 90 percent of its maximum dry density. The upp.er
twelve inches of subgrade beneath paved areas should be compacted to 95 percent of the mat~s maximum
dry density. This compaction should be obtained by the paving contractor just prior to placing the aggregate
base material and should not be part of the grading requirements or operation.
All grading and fill placement should be performed in accordance with the City of Carlsbad Grading
Requirements, the Uniform Building Code, and the attached Recommended Grading Specifications and
Special Provisions attached hereto as Appendix B.
SURFACE DRAINAGE: Pad drainage should be designed to collect and direct surface water away from the
proposed structure and toward approved drainage areas. For earth areas, a minimum gradient of one percent
should be maintained. The ground around the proposed building should be graded so that surface water flows
rapidly away from the building without ponding. In general, we recommend that the ground adjacent to
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C\'\7E 200.298 June 21, 2000 Page No. 10
buildings slope away at a gradient of at least two percent Densely vegetated areas where ru,noff can be impllired
should have a minimum gradient of five percent within the first five feet from the structure.
GRADING PLAN REVIEW: If a site grading plan is necessary, it should be submitted to this office for
review in order to ascertain that the recommendations contained in this report have been implemented, and
that no additional recommendations are needed due to changes in the anticipated development plans.
FOUNDATION RECOMMENDATIONS
GENERAL: Our investigation indicated that the proposed structure may be supported by conventional
~hallow foundations founded in properly-compacted structural fill. It is anticipat~d the fill materials at the
bearing depths will be moderately expansive. The recommendations contained herein reflect this condition.
Spread footings supporting the proposed office building should be embedded at least 24 inches below the
finish pad grade. Continuous and isolated footings should have a minimum width of 18 inches and 24 inches,
respectively.
BEARING CAPACITY: Conventional spread footings with the above recommended minimum dimensions
may be designed for an allowable soil bearing pressure of 2,000 pounds per square foot. These values may be
increased by 300 pounds per square foot and 150 pounds per square foot for each additional foot of footing
embedment and width, respectively, up to a maximum bearing capacity of 3,000 pounds per square foot.
Additionally, the bearing capacity may be increased by one-third for combinations of temporary loads such as
those due to wind or seismic loads.
FOOTING REINFORCING: Reinforcement requirements for foundations should be provided by a
structural engineer. However, based on the anticipated soil conditions, we recommend that the minimum
reinforcing for continuous footings consist of at least two No.5 bars positioned three inches above 1;he bottom
of the footing and two No.5 bars positioned approximately two inches below the top of the footing.
LATERAL LOAD RESISTANCE: Lateral loads against foundations may be resisted by friction between the
bottom of the footing and the supporting soil, and by the passive pressure against the footing. The coefficient
of friction between concrete and soil may be considered to be 0.30. The passive resistance may be considered
to be equal to an equivalent fluid weight of 300 pounds per cubic foot. 'Ibis assumes the footings are poured
tight against undisturbed soil. If a combination of the passive pressure and friction is used, the friction value
should be reduced by one-third.
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C\VE 200.298 June 21, 2000 PngeNo.ll
FOUNDATION EXCAVATION OBSERVATION: All foundation excavations should be observed by the
Geotechnical Consultant prior to placing concrete to determine if the foundation recommendations presented
herein are complied with. All footing excavations should be excavated neat, level and square. All loose or
unsuitable material should be removed prior to the placement of concrete.
ON-GRADE SLABS
INTERIOR FLOOR SLABS: The minimum slab thickness for the proposed office building should be five
inches (actual) and should be reinforced with at least No.3 reinforcing bars placed at 18 inches on center
each way. Slab reinforcement should be supported on chairs such that the reinforcing bars are positioned at
mid-height in the floor slab. The slab reinforcement should extend into the perimeter foundations at least six
inches.
MOISTURE PROTECTION FOR INTERIOR SLABS: Where the concrete on-grade floor slab will
support moisture-sensitive floor covering, it should be underlain by a moisture barrier. We recommend that the
minimum configuration of the subs lab moisture barrier consist of a four-inch-thick blanket of coarse, clean
sand. The moisture barrier material should have less than ten percent and five percent passing the No.-100 and
No. 200 sieves, respectively. A visqueen vapor barrier should be placed in the center of the moisture protection
blanket Our experience indicates that this moisture barrier should allow the transmission of from about 6 to 12
pounds of moisture per 1000 square feet per day through the on-grade slab. This may be an excess 'amount of
moisture for some types of floor covering. If additional protection is considered necessary, additional
recommendations can be provided
EXTERIOR CONCRETE FLATWORK: Exterior slabs should have a minim~ thickness ?f four inches.
Reinforcement and control joints should be constructed in exterior concrete flatwork to reduce the potential
for cracking and movement Joints should be placed in exterior concrete flatwork to help control the location
of shrinkage cracks. Spacing of control joints should be in accordance with the American Concrete Institute
specifications.
PRELIMINARY PAVEMENT SECTIONS
TRAFFIC INDEX: In consideration of the type of traffic that is expected to be generated by the proposed
structure, traffic indexes of 5.5 and 4.5 were assumed for the driveway and parking areas, respectively, in order
to determine the required structural pavement sections. This assumes general light truck and automobile traffic
with occasional moving vans and weekly trash trucks.
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CWE200.298 June 21, 2000 Page No. 12
R-VALUE TEST: An R-Value test has been performed on the material that is expected to be present inmost
of the pavement subgrade. Results of our laboratory testing indicated the subgrade soils have an approximate
R -Value of 23. This value \Vas used in determining the preliminary structural pavement sections presented
hereinafter. We recommend that when the site grading is completed, representative samples of the subgrade soil
be obtained and tested for their R-Value so that final pavement design recommendations can be provided.
PRELIMINARY STRUCTURAL SECTION: Based on the above parameters, it was determined that the
preliminary structural pavement section should consist of the following sections;
Driveways and Trash Truck Routes (TI = 5.5)
3.0 Inches of Asphalt Concrete pavement
on 9.0 Inches of Crushed Aggregate Base
General Parking Areas (TI = 4.5)
3.0 Inches of Asphalt Concrete Pavement
on 6.0 Inches of Crushed Aggregate Base.
Prior to placing the base material, the subgrade soils should be scarified to a depth of 12 inches, moisture
conditioned and compacted to at least 95 percent of its maximum dry density. The Crushed Aggregate Base
material should conform to the requirements set forth in Section 200-2.2 of the Standard Specifications for
Public Works Construction. All paving methods and materials should conform with good engineering and
paving practices and to the requirements of the City of Carlsbad.
LIMITATIONS
REVIEW, OBSERVATION AND TESTING
The recommendations presented in this report are contingent upon our review of final plans and specifications.
Such plans and specifications should be made available to the Geotechnical Engineer and Engineering Geologist
so that they may review and verify their compliance with this report
It is recommended that Christian Wheeler Engineering be retained to provide continuous soil engineering
services during the earthwork operations. This is to verify compliance with the design concepts, specifications
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CWE200.298 June 21,2000 Page No. 13
or recommendations and to allow design changes in the event that subsurface conditions differ from those
anticipated prior to start of construction.
UNIFORMITY OF CONDITIONS
The recommendations and opinions expressed in this report reflect our best estimate of the project
requirements based on an evaluation of the subsurface soil conditions encountered at the subsurface exploration
locations and on the assumption that the soil conditions do not deviate appreciably from those encountered. It
should be recognized that the performance of the foundations and/or cut and fill slopes may be influenced by
undisclosed or unforeseen variations in the soil conditions that may occur in the intermediate and unexplored
areas. Any unusual conditions not covered in this report that may be encountered during site development
should be brought to the attention of the Geotechnical Engineer so that he may make modifications if
necessary.
CHANGE IN SCOPE
This office should be advised of any changes in the project scope or proposed site grading so' that we may
determine if the recommendations contained herein are appropriate. It should be verified in writing if the
recommendations are found to be appropriate for the proposed changes or our recommendations should be
modified by a written addendum.
TIME liMITATIONS
The findings of this report are valid as of this date. Changes in the condition of a property can, however, occur
with the passage of time, whether they are due to natural processes or the work of ~ on this or adjacent
properties. In addition, changes in the Standards-of-Practice and! or Government Codes may occur. Due to
such changes, the findings of this report may be invalidated wholly or in part by changes beyond our controL
Therefore, this report should not be relied upon after a period of two years without a review by us verifylng the
suitability of the conclusions and recommendations.
PROFESSIONAL STANDARD
In the performance of our professional services, we comply with that level of care and skill ordinarily exercised
by members of our profession currendy practicing under similar conditions and in the same locality. The client
recognizes that subsurface conditions may vary from those encountered at the locations where our borings,
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CWE200.298 June 21, 2000 Page No. 14
surveys, and explorations are made, and that our data, interpretations, and recommendations are based solely on
the information obtained by us. We will be responsible for those data, interpretations, and recommendations,
but shall not be responsible for the interpretations by others of the information developed. Our services consist
of professional consultation and observation only, and no warranty of any kind whatsoever, express or implied,
is made or intended in connection with the work performed or to be performed by us, or by our proposal for
consulting or other services, or by our furnishing of oral or written reports or findings.
CliENT'S RESPONSIBILITY
It is the responsibility of Prentiss Properties, or their representatives, to ensure that the information and
recommendations contained herein are brought to the attention of the structural engineer and architect for the
project and incorporated into the project's plans and specifications. It is further their responsibility to take the
necessary measures to insure that the contractor and his subcontractors carry out such recommendations during
construction.
FIELD EXPLORATIONS
Nine subsurface explorations were made at the locations indicated on the site plan included herewith as Plate
Number 1 on :May 22 and May 24, 2000. These explorations consisted of seven test borings drilled with a truck-
mounted drill rig and two hand-augered test pits. The fieldwork was conducted under the observation and
direction of our engineering geology personnel
The explorations were carefully logged when made. The boring logs are presented on the following Plate
Numbers 2 through 10. The soils are described in accordance with the Unified Soils Classification. In addition,
a verbal textural description, the wet color, the apparent moisture and the density or consistency are provided.
The density of granular soils is given as either very loose, loose, medium dense, dense or very dense. The
consistency of silts or clays is given as either very soft, soft, medium stiff, stiff, very stiff, or hard
Disturbed and relatively undisturbed samples of typical and representative soils were obtained and returned to
the laboratory for testing. The undisturbed samples were obtained by driving a 2 and 3/8-inch inside diameter
split-tube sampler ahead of the auger using a 140-pound weight free-falling a distance of 30 inches. The number
of blows required to drive the sampler each foot was recorded and this value is presented on the attached boring
logs as ''Penetration Resistance." Bulk samples of disturbed soil samples were also collected in bags froin the
auger cuttings during the advancement of the borings and returned to the laboratory for testing.
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CWE200.298 June 21, 2000 Page No. 15
LABORATORY TESTING
Laboratory tests were perfonned in accordance with the generally accepted American Society for Testing and
Materials (ASTM) test methods or suggested procedures. A brief description of the tests performed is
presented below.
a) CLASSIFICATION: Field classifications were verified in the laboratory by visual e."l:amination. The
final soil classifications are in accordance with the Unified Soil Classification System.
b) MOISTURE-DENSITY: In-place moisture contents and dry densities were determined for
representative soil samples. This information was an aid to classification and permitted recognition of
variations in material consistency with depth. The dry unit weight is determined in pounds per cubic
foot, and the in-place moisture content is determined as a percentage of the soil's dry weight The
results of these tests are summarized in the exploration logs.
c) GRAIN SIZE DISTRIBUTION: The grain size distribution was determined from a representative
sample of the alluvial soils in accordance with ASTM D422 The results of this test are presented on
Plate Number 11.
d) DIRECf SHEAR TEST: A direct shear test was performed to determine the failure envelope
based on yield shear strength. The shear box was designed to accommodate a sample having a
diameter of 2.375 inches or 2.50 inches and a height of 1.0 inch. Samples were tested at different
verrlcalloads and at a saturated moisture content. The shear stress was applied at a constant r~te of
strain of approximately 0.05 inch per minute. The results of this test are presented on the attached
Plate Number 11.
e) COMPACTION TEST: The maximum dry density and optimum moisture content of typical soils
was determined in the laboratory in accordance with ASTM Standard Test D-1557 -91. The results of
this test are presented on Plate Number 11.
f) EXPANSION INDEX TEST: An expansion index test was perfonned on a representative sample
of the clayey subsoil found near the surface of the site. The test was perfonned on the'portion of
the sample passing the #4 standard sieve. The sample was brought to optimum moisture content
and then dried back to a constant moisture content for 12 hours at 230 + 9 degrees Fahrenheit.
The specimen was then compacted in a 4-inch-diameter mold in two equal layers by means of a
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C\VE 200.298 June 21,2000 Page No. 16
tamper, then trimmed to a final height of 1 inch, and brought to a saturation of approximately 50
percent. The specimen was placed in a consolidometer with porous stones at the top and bottom,
a total normal load of 12.63 pounds was placed (144.7 psf), and the sample was allowed to
consolidate for a period of 10 minutes. The sample was saturated, and the change in vertical
movement was recorded until the rate of expansion became nominal. The expansion index is
reported on Plate Number 11 as the total vertical displacement times the fraction of the sample
passing the #4 sieve times 1000.
g) RESISTANCE VALUE (R-VALUE) TEST: The Resistance Value of a representative sample of
the anticipated subgrade soil was determined in accordance with California Test Method 301. 'An
R-value of23 resulted from our testing; the test results are presented on Plate No. 12
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Tht::>~-bk l~1C-( u.&.td . ..
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~ PRENTISS PROPERTies
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1m _cu..f",~ 1!2I.....-..... w...,. .........
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......... ~-=-.................. ~ .... -'"'
WfQ".1 ... at.. .., ... ............ ... .... "', ....
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.... ="':...-.::..--=-...:
CARLSBAD PACIFIC CENTER • PARCEL III
70S PALOMAR AIRPORT RD. • CARLSBAD I CAUFORNIA
~2fhv-e-~~~ ~ ~~?I.7ceQI .1~r.{~J#r.·.
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LEGEND
BY:
re APPROXIMATE BORING TEST LOCATION I
:-. ' APPROXIMATE TEST PIT LOCATION
W
I
CHRISTIAN WHEELER
ENGINEERING
'CARLSBAD PACIFIC CENTER' BLDG III
, CGC/He DATE: JUNE 2000
JoaNO: , 200.298.1 PLATE NO: 1
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LOG OF TEST BORING NUMBER B-1
Date Excavated: OS/22/00
CME55
+ 55 feet
1401bs.
Equipment:
Surface Elevation:
Hammer Weight:
'P' <..? 0 C1) ..al t-1 "'--'" U ~ H :r: SUMMARY OF SUBSURFACE CONDITIONS tt ~ Q <..?
TOPSOIL: Medium brown, dry, loose, fine-to medium-grained,
2 SILTY SAND
TERRACE DEPOSITS (Qt); Medium brown to gray, moist,
4 dense, fine-to medium-grained, CLAYEY SAND (sq with trace
voids. Becomes dense at two feet beolw the surface.
6 Boring terminated at five feet
No groundwater encountered.
8
10
12
16
18
Logged by: DRR
Project Manager: CHC
Depth to Water: N / A
Drop of Hammer: 30 inches
-e-~ fil ~ ~ ~ ~
~ ::J Z ~ ::J
~ H ~ Q 0 ~ Cl
50-6" 7.9 120.0
us 50-3"
C/'j
f:-4 CI) ~
RV
20~-L----------------------------------------~~--~~--~--~~
'W
CHRlSl1A1\J WHEELER.
ENGINEER.ING
BY:
Proposed Carlsbad Pacific Center Phase III
705 Palomar Airport Road, Carlsbad, California
CGC DATE: une 2000
]OBNO. 200.298 PLATE NO.: 2
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LOG OF TEST BORING NUMBER B-2
Date Excavated: OS/22/00
C1vfE 55
+ 55 feet
Equipment:
Surface Elevation:
Hammer Weight: 140lbs.
'Z' CJ 9 CI.l ~ ......, U ~ ~ ~ SUMMARY OF SUBSURFACE CONDITIONS
fa ~ 0 CJ
TOPSOIL: Light brown, dry, loose, fine-to medium-grained,
SILTY SAND
Logged by: DRR
Project Manager: CHC
Depth to Water: N/ A
Drop of Hammer: 30 inches
'0' .~ ~ ~
~ "-"
~ t:
~ ~ z ~ ::J
~ ~ .~
Q P:: Cl
WEATHERED TERRACE DEPOSITS (Ot): Medium brown, 23 10.5 104.4
SANDY CLAY voids.
CLAYEY SAND US 50-5"
6
Boring tenninated at five feet.
8 No groundwater encountered.
18
C/.l t:;
~ E-<
20~-L----------------------------------------~--~~--~--~--~--~
!N
CHRlSllAN WHEaER. BY:
ENGINEER.ING ]OBNO.
Proposed Carlsbad Pacific Center Phase III
705 Palomar Airport Road, Carlsbad, California
CGC DATE: une 2000
200.298 PLATE NO.: 3
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LOG OF TEST BORING NUMBER B-3
Date Excavated: OS/22/00
Equipment: CME55
Surface Elevation: + 55 feet
Hammer Weight: 140 lbs.
14
16
18
SUMMARY OF SUBSURFACE CONDITIONS
TERRACE DEPOSITS (00: Light brown to medium brown,
damp to moist, medium dense, fine-to medium-grained,
CLAYEY SAND (sq.
Becomes dense.
Boring terminated at five feet.
No groundwater encountered.
Logged by: DRR
Project Manager: CHC
Depth to Water: N/A
Drop of Hammer: 30 inches
SAMPLES
US 7.0 98.9
US 67
20L--L----------------------------------------~--~~~~--~--~--~
!N
CHRISTIAN WHEELER.
ENGINEER.ING
BY:
Proposed Carlsbad Pacific Center Phase III
705 Palomar Airport Road, Carlsbad, California
CGC DATE: upe 2000
]OBNO. 200.298 ' PLATE NO.: 4
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LOG OF TEST BPRING NUMBER B-4
Date Excavated: OS/22/00 Logged by: DRR
Equipment: CME55 Project Manager: CHC
Surface Elevation: ± 55 feet Depth to Water: N/A
Hammer Weight: 1401bs. Drop of Hammer: 30 inches.
'0' 0 0 "0' ~ CI) p::J .~
<2 ~ ~ '-'" U ~ ~ t: C/)
,...; ~ ::r: SUMMARY OF SUBSURFACE CONDITIONS ~ :J Z
fb ~ ~ :::> ~
Q ,...; ~ 0 Q ~ Q
FILL (Qaf): Medium brown, very wet to saturated, loose to
2
medium dense, fine-to medium-grained, CLAYEY SAND (sq
16.1 1121
with a trace amount of gravel.
4
WEATHERED TERRACE DEPOSITS (Qt): Medium brown,
moist, stiff to stiff, SANDY CLAY US 35
6
Boring terminated at five feet.
8 No groundwater encountered.
10
12
14
16
18
20L-~----------------------------------------~~~~--~--~~~--~
CHRISTIAN WHEELER.
ENGINEER.ING
BY:
Proposed Carlsbad Pacific Center Phase III
705 Palomar Airport Road, Carlsbad, California
CGC DATE: une 2000
]OBNO. 200.298 PLATE NO.: 5
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LOG OF TEST BORING NUMBER B-5
Date Excavated: OS/22/00
CMESS
+ 55 feet
Logged by: DRR
Project Manager: CHC
Depth to Water: N/A
Drop of Hammer: 30 inches
Equipment:
Surface Elevation:
Hammer Weight: 1401bs.
SUMMARY OF SUBSURFACE CONDITIONS
FIll.. (Oat): Dark brown to gray, wet to saturated, loose to
medium dense, CLAYEY SAND (SC).
TERRACE DEPOSITS (Qt): Light brown, moist, dense, fine-to
medium-grained, CLAYEY SAND (SC).
Medium brown, moist, stiff, SANDY CLAY eCL).
Gray, moist, dense, fine-to medium-grained, CLAYEY SAND (SC)
with abundant iron stains.
Boring terminated at 20 feet. No groundwater encountered.
SAMPLES
us 20.9 lOO.9
US 61 11.2 118.2
US '32 '25.9 96.9
us 32 31.1' 88.9
us 64
-
Proposed Carlsbad Pacific Center Phase III
705 Palomar Airport Road, Carlsbad, California
SA,EI, .
!N
CGC DATE: une 2000 BY: CHRlSl1AN WHEELER.
ENGINEERING ]OBNO. 200.298 PLATE NO.: 6
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LOG OF TEST BORING NUMBER B-6
Date Excavated: OS/22/00
Equipment: CME55
Surface Elevation: + 55 feet
Hammer Weight: 1401bs.
SUMMARY OF SUBSURFACE CONDITIONS
FILL (Pat): Dark brown, wet, soft, SANDY CLAY (CL).
TERRACE DEPOSITS (Pt): Orangish-brown, moist, medium
dense, fine-to medium-grained, CLAYEY SAND (SC).
Medium brown, moist, stiff, SANDY CLAY (CL) with abundant
caliche.
Grades to gray and very stif£
Light brown to gray, moist, medium dense to dense, flne-to
medium-grained, CLAYEY SAND (SC) with slight iron stains.
Boring terminated at 20 feet. No groundwater encountered.
Logged by: DRR
Project IYfanager: CHC
Depth to Water: N/A
Drop of Hammer: 30 inches
SAMPLES
US 11.4 121.4
us 127 "116.7
US 18 26.3 97.5
US 44
US 53
Proposed Carlsbad Pacific Center Phase IIi
705 Palomar Airport Road, Carlsbad, California
BY: CGC
]OBNO. 200.298
CHRISTIAN WHEELER.
ENGINEERING
DATE: une 2000
PLATE NO.: 7
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LOG OF TEST BORING NUMBER B-7
Date Excavated: OS/22/00
CME55
+ 55 feet
140 lbs.
Logged by: DRR
Project Manager: CHC
Depth to Water: N/A
Drop of Hammer: 30 inches
Equipment:
Surface Elevation:
Hammer Weight:
;.." .. ~ ..
" "
SUM1vfARY OF SUBSURFACE CONDITIONS
FILL (Qat): Gray to medium brown, wet to saturated, soft,
SANDY CLAY (CL).
WEATHERED TERRACE DEPOSITS (Qt): Medium brown,
moist, stiff, SANDY CLAY (CL).
TERRACE DEPOSITS (Ot): Light brown, moist, medium dense,
fine-to medium-grained, CLAYEY SAND (SC) with occasional
iron 5 taining.
Gray. moist, medium dense, fine-to medium-grained, POORL Y-
us 7 20.1 104.5
us 14.0 114.8
us 26 26.0 95.4
us 53 13.5 118.4
us 38
:. "" GRADED SAND 20~~--~~~~~~~----------------------~~~--~~--------~ Boring terminated at 20 feet No groundwater encountered.
CHRlSllAN WHEELER.
ENGINEER.ING
BY:
Proposed Carlsbad Pacific Center Phase III
705 Palomar Airport Road, Carlsbad, California
CGC DATE: une 2000
JOB NO. 200.298 PLATE NO.: 8
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LOG OF TEST PIT NUMBER P-l
Date Excavated: OS/24/00 Logged by:
Equipment: Hand Auger Project Manager:
Existing Grade Cft): + 55 feet Depth to Water::
Finish Grade (ft): ± 55 feet Drop of Hammer:
SAMPLES
0 0 ~
U ~ ~
it ~ Q 0
6
SUMMARY OF SUBSURFACE CONDITIONS
Fill: Greenish-brown and orangish-brown, wet, loose to medium
dense/medium stiff, CLAYEY SAND-SANDY CLAY (SC-CL) w/
four inches of sod material on the
Dark reddish-brown, very moist, dense, CLAYEY-SAND (SC).
Test Pit terminated at 4 feet due to meeting refusal with hand auger.
No groundwater encountered.
I:I.1 ~ ~
::s ~ ::J
~ ~
U)
JAB
CHC
N/A
N/A
~ I:I.1 'CO' ~ ~ ~ "--' .~ ~ ~ ::J Z Z ~ ::J
::J 1-"-1 ~ ~ 0 ~ Q 0
Proposed Carlsbad Pacific Center Pp.ase III .. !. 705 Palomar Airport Road, Carlsbad, California
CHRlSTIAN WHEELER. BY: CGC DATE: une 2000
ENGINEER.ING OB NO. : 200.298 PLATE NO.: 9
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LOG OF TEST PIT NUMBER P-2
Date Excavated: OS/24/00 Logged by:
Equipment: Hand Auger Project Manager:
Existing Grade (ft): + 55 feet Depth to Water::
Finish Grade (ft): + 55 feet Drop of Hammer:
SAMPL ES
c.9 S
U fS ..... :r:
~ ~ Q 0
4
5
6
7
9
SU11MARY OF SUBSURFACE CONDITIONS
Fill: Greenish-brown and orangish-brown, wet, loose to medium
dense/medium stiff, CLAYEY SAND-SANDY CLAY (SC-CL) w/
four inches of
Reddish-brown, moist, dense, CLAYEY-SAND (sq.
TERRACE DEPOSITS (Ot): Dark reddish-brown, moist, dense/
very stiff, CLAYEY SAND-SANDY CLAY
Test Pit terminated at 3 feet due to meeting refusal with hand auger.
No groundwater encountered.
~ ~ ~ ~ .....:l ::> ~ ~
en
JAB
CHC
N/A
N/A
~ 'C' ~ ~ ~ '-'
~ ~ t:: :::J Z Z 'f-! ::> ::> C/) ..... ~ ~ ~ c.9 Q
W
Proposed Carlsbad Pacific Center Phase III
705 Palomar Airport Road, Carlsbad, California
CHRISTIAN WHEELER. BY: CGC DATE: une 2000
ENGINEERING OBNO.: 200.298 PLATE NO,: , 10
C/)
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LABORATORY TEST RESULTS
CARLSBAD PACIFIC CENTER OFFICE BUILDING PHASE III
705 PALOMAR AIRPORT ROAD
DIRECT SHEAR TEST
Sample Number
Description
Angle of Friction
Apparent Cohesion
CARLSBAD, CALIFORNIA
Boring No.5 @ 0 -3%'
Remolded
15 Degrees
250 psf
GRAIN SIZE DISTRIBUTION
Sample Number
Sieve Size
#4
#8
#16
#30
#50
#100
#200
Classification
Boring No.5 @ 0' -3%'
Percent Passing
100
100
99
95
83
61
45
SC
MAXIMUM DENSITY/OPTIMUM MOISTURE CONTENT
Sample Number
Description
Maximum Density
Optimum Moisture Content
EXPANSION INDEX TEST
Sample Number
Description
Initial Moisture Content
Initial Dry Density
Final Moisture Content
Expansion Index
Classification
CWE200.298
Boring No.5 @ 0' -3%'
Clayey Sand (SC)
124.1 pef
8.6 Percent
Boring No.5 @ 0' -3%'
Clayey' Sand (SC)
8.3 Percent
106.6 pef
20.0 Percent
29
Low
June 21, 2000 Plate No. 11
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SAMPLE: Boring No.1 @ 112'-5'
TEST SPECIMEN A B C D E
DATE TESTED 6/14/00 6/14/00 6/14/00
Compactor Air Pressure psi 80 165 260
Initial Moisture % 3.6 3.6 3.6
Moisture at Compaction % 12.6 11.3 10.3
Briquette Heiglit In. 2.56 2.57 2.54
Density pcf 119.0 121.6 123.9
EXUDATION PRESSURE psi 220 375 765
EXPANSION PRESSURE DIAL 82 160 255
Ph-at 1000 pounds psi 56 46 23
Ph at 2000 pounds psi 125 104 53
Displacement turns 3.85 3.45 3.30
"R" Value 16 28 61
CORRECTED "R"VALUE 16 29 61
"R" Value at 300 psi Exudation Pressure = 23
"R" Value by Expansion =26
100
GRAIN SIZE DISTRIBUTION
SIEVE AS AS 90
RECEIVED TESTED
3
21/2 80
2
11/2
1 70
3/4
1/2 60
3/8 ~ #4
#8 ~ 50
#16 ~ #30
#50 40
#100
#200 30
0.05mm
0.OO5mm ..
0.001mm 20
LIQUID LIMIT
PLASTIC LIMIT
PLASTICITI INDEX 10
SAND EQUIVALENT
0
800 750 700 650 600 550 500 450 400 350 300 250 200 150 100 50' 0
EXUDATION PRESSURE psi
!N BY; CGC DATE: June 2000
CHRISTIAN WHEELER UOBNO.: 200.298 PLATE: 12 ENGINEER-ING
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eWE 200.298 June 21, 2000 Appendi.'{ A, Page Al
REFERENCES
Anderson, J .G.; Rockwell, R.K. and Agnew, D .c., 1989, Past and Possible Future Earthquakes
of Significance to the San Diego Region, Earthquake Spectra, Volume 5, No.2, 1989.
California Division of Mines and Geology, 1998, Maps of Known Active Fault Near Source-Zones in California
and Adjacent Portions of Nevada.
CalifQrnia Division of Mines and Geology, 1997, Guidelines for Evaluating and Mitigating Seismic Hazards in
California, Special Publication 117.
Tan, S.S. and Kennedy, M.P., 1996, Geologic Map of the Encinitas and Rancho Santa Fe 7.5' Quadrangles, San
Diego County, California, California Division of Mines and Geology, Open-File Report, Scale 1:24,000.
Federal Emergency Management Agency, 1997, San Diego County, California and Incorporated Areas Flood
Insurance Rate Map, Panel 1027 of2375, Map Number 06073C1027 F.
Jennings, C.W., 1975, Fault Map of California, California Division of Mines and Geology, Map
No.1, Scale 1:750,000.
Kern, P., 1989, Earthquakes and Faults in San Diego County, Pickle Press, 73 pp.
Hart, E.W., 1994, Fault-Rupture Hazard Zones in California, California Division of Mines and Geology Special
Publication 42.
Mualchln, L and Jones, A.L, 1992, Peak Acceleration from Maximum Credible Earthquakes in
California (Rock and Stiff-Soil Sites) California Division of Mines and Geology Open-File Report 92-1.
Wesnousky, S.G., 1986, "Earthquakes, Quaternary Faults, and Seismic Hazards in California", in
Journal of Geophysical Research, Volume 91, No. B 12, pp 12,587 to 12,631, November1986.
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eWE 200.298 June 21, 2000 Appendix A,. Page A2
TOPOGRAPHIC MAPS
County of San Diego, 1963,200 Scale, Topographic Map, Sheet 346-1671.
County of San Diego, 1975,200 Scale, Ortho-Topo Map, Sheet 346-1671.
PHOTOGRAPHS
San Diego County, 1963, Flight 12, Photographs 1, 2, and 3; Scale 1 inch = 1000 feet (approximate) .
San Diego County, 1970, Flight 2, Photograph 1; Scale 1'inch = 1000 feet (approximate).
San Diego County, 1970, Flight 3, Photographs 4 and 5; Scale 1 inch = 1000 feet (approximate).
San Diego County, 1975, Flight 35, Photographs 6 and 7; Scale 1 inch = 1000 feet (approximate).
San Diego County, 1979, Flight 14, Photographs B25 and B26; Scale 1 inch = 1000 feet (approximate).
San Diego County, 1983, Photographs 244, 245, and 256; Scale 1 inch = 2000 feet (approximate).
San Diego County, 1989, Photographs 3-5 and 3-7; Scale 1 inch = 2000 feet (approximate).
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C\'VE 200.298 June 21, 2000 Appendi.'C Bj Page Bl
RECOMMENDED GRADING SPECIFICATIONS -GENERAL PROVISIONS
PROPOSED CARLSBAD PACIFIC CENTER PHASE III OFFICE BUILDING
705 PALOMAR AIRPORT ROAD
CARLSBAD. CALIFORNIA
GENERAL INTENT
The intent of the.se specifications is to establish procedures for clearing, compacting natural ground,
preparing areas to be filled, and placing and compacting fill soils to the lines and grades shown on the
accepted plans. The recommendations contained in the preliminary geotechnical investigation report and/or
the attached Special Provisions are a part of the Recommended Grading Specifications and shall supersede
the provisions contained hereinafter in the case of conflict. These specifications shall only be used in
conjunction with the geotechnical report for which they are a part. No deviation from these specifications
will be allowed, except where specified in the geotechnical report or in other written communication signed
by the Geotechnical Engineer.
OBSERVATION AND TESTING
Christian Wheeler Engineering shall be retained as the Geotechnical Engineer to observe and test the
earthwork in accordance with these specifications. It will be necessary that the Geotechnical Engineer or his
representative provide adequate observation so that he may provide his opinion as to whether or not the
work was accomplished as specified. It shall be the responsibility of the contractor to assist the Geotechnical
Engineer and to keep him appraised of work schedules, changes and new information and data so that he
may provide these opinions. In the event that any unusual conditions not covered by the special provisions
or preliminary geotechnical report are encountered during the grading operations, the Geotechnical Engineer
shall be contacted for further recommendations.
If, in the opinion of the Geotechnical Engineer, substandard conditions are encountered, su2h as
questionable or unsuitable soil, unacceptable moisture content, inadequate compaction, adverse weather, etc.,
construction should be stopped until the conditions are remedied or corrected or he shall recommend
rejection of this work.
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CWE200.298 June 21, 2000 Appendix B, Page B2
Tests used to determine the degree of compaction should be performed in accordance with the following
American Society for Testing and Materials test methods:
Ma.-runum Density & Optimum Moisture Content -ASTM D-1557-91
Density of Soil In-Place -ASTM D-1556-90 or ASTM D-2922
All densities shall be expressed in terms of Relative Compaction as determined by the foregoing ASTM
testing procedures.
PREPARATION OF AREAS TO RECEIVE FILL
All vegetation, brush and debris derived from clearing operations shall be removed, and legally disposed of.
All areas disturbed by site grading should be left in a neat and finished appearance, free from unsightly debris.
After clearing or benching the natural ground, the areas to be filled shall be scarified to a depth of 12 inches,
brought to the proper moisture content, compacted and tested for the specified minimum degree of
compaction. A11loose soils in excess of 6 inches thick should be removed to firm natural ground which is
defined as natural soil which possesses an in-situ density of at least 90 percent of its maximum dry density.
When the slope of the natural ground receiving fill exceeds 20 percent (5 horizontal units to 1 vertical unit),
the original ground shall be stepped or benched. Benches shall be cut to a firm competent formational soil.
The lower bench shall be at least 10 feet wide or 1-1/2 times the equipment width, whichever is greater, and
shall be sloped back into the hillside at a gradient of not less than two (2) percent All other benches should
be at least 6 feet wide. The horizontal portion of each bench shall be compacted prior to receiving fill as
specified herein for compacted natural ground. Ground slopes flatter than 20 percent shall be benched when
considered necessary by the Geotechnical Engineer.
Any abandoned buried structures encountered during grading operations must be totally removed. All
underground utilities to be abandoned beneath any proposed structure should be removed from within 10
feet of the structure and properly capped off. The resulting depressions from the above described procedure
should be backfilled with acceptable soil that is compacted to the requirements of the Geotechnical Engineer.
This includes, but is not limited to, septic tanks, fuel tanks, sewer lines or leach lines, storm drains and water
lines. Any buried structures or utilities not to be abandoned should be brought to the attention of the
Geotechnical Engineer so that he may determine if any special recommendation will be necessary.
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C\VE 200.298 June 21, 2000 Appendi.'C B, Page B3
FILL MATERIAL
Materials to be placed in the fill shall be approved by the Geotechnical Engineer and shall be free of organic
matter and other deleterious substances. Granular soil shall contain sufficient fine material to fill the voids.
The definition and disposition of oversized rocks and expansive or detrimental soils ate covered in the
geotechnical report or Special Provisions. Expansive soils, soils of poor gradation, or soils with low strength
characteristics may be thoroughly mixed with other soils to provide satisfactory fill material, but only with the
explicit consent of the Geotechnical Engineer. Any import material shall be approved by the Geotechnical
Engineer before being brought to the site.
PLACING AND COMPACTION OF FILL
Approved fill material shall be placed in areas prepared to receive fill in layers not to exceed 6 inches in
compacted thickness. Each layer shall have a uniform moisture content in the range that will allow the,
compaction effort to be efficiently applied to achieve the specified degree of compaction. Each layer shall be
uniformly compacted to the specified minimum degree of compaction with equipment of adequate size to
economically compact the layer. Compaction equipment should either be specifically designed tor soil
compaction or of proven reliability. The minimum degree of compaction to be achieved is 'specified ,in either '
the Special Provisions or the recommendations contained in the preliminary geotechnical investigation
report.
When the structural fill material includes rocks, no rocks will be allowed to nest and all voids must be
carefully filled with soil such that the minimum degree of compaction recommended in the Special
Provisions is achieved. The maximum size and spacing of rock permitted in structural fills and in non-
structural fills is discussed in the geotechnical report, when applicable.
Field observation and compaction tests to estimate the degree of compaction of the fill will be taken by the
Geotechnical Engineer or his representative. The location and frequency of the tests shall be at the
Geotechnical Engineer's discretion. When the compaction test indicates that a particular layer is at less than
the required degree of compaction, the layer shall be reworked to the satisfaction of the Geotechnical
Engineer and until the desired relative compaction has been obtained
Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Compaction by
sheepsfoot roller shall be at vertical intervals of not greater than four feet. In addition, fill slopes at a ratio of
two horizontal to one vertical or flatter, should be trackrolled. Steeper fill slopes shall be over-built and cut-
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CWE200.298 June 21, 2000 Appendix B, Page B4
back to' finish contours after the slope has been constructed. Slope compaction operations shall result in all
fill material six or more inches inward from the finished face of the slope having a relative compaction of at
least 90 percent of maximum dry density or the degree of compaction specified in the Special Provisions
section of this specification. The compaction operation on the slopes shall be continued until the
Geotechnical Engineer is of the opinion that the slopes will be surficially stable.
Density tests in the slopes will be made by the Geotechnical Engineer during construction of the slopes to
determine if the required compaction is being achieved. Where failing tests occur or other field problems
arise, the Contractor will be notified that day of such conditions by written communication from the
Geotechnical Engineer or his representative in the form of a daily field report.
If the method of achieving the required slope compaction selected by the Contractor fails to produce the
necessary results, the Contractor shall rework or rebuild such slopes until the required degree of compaction
is obtained, at no cost to the Owner or Geotechnical Engineer.
CUT SLOPES
The Engineering Geologist shall inspect cut slopes excavated in rock or lithified formational material during §
the grading operations at intervals determined at his discretion. If any conditions not anticipated in the
preliminary report such as perched water, seepage, lenticular or confined strata of a potentially adverse
nature, unfavorably inclined bedding, joints or fault planes are encountered during grading, these conditions
shall be analyzed by the Engineering Geologist and Geotechnical Engineer to determine if mitigating
measures are necessary.
Unless otherwise specified in the geotechnical report, no cut slopes shall be excavated higher or steeper than
that allowed by the ordinances of the controlling governmental agency.
ENGINEERING OBSERVATION
Field observation by the Geotechnical Engineer or his representative shall be made during the filling and
compaction operations so that he can express his opinion regarding the conformance of the grading with
acceptable standards of practice. Neither the presence of the Geotechnical Engineer or his representative or
the observation and testing shall release the Grading Contractor from his duty to compact ali fill material to
the specified degree of compaction.