HomeMy WebLinkAboutParcel 19 Updated Geotechnical Investigation
I: ~EN C01"Qoration
. Soil Enginetling and Consul!ingServices. Engineering Geology . Compaction Testing
-Inspections. Conslruclion MalerialsTesting. LaboraloryTesling . Percolalionl"esling
-Geology. Water Resource Studies . Phase I & II Environmental Site Assessmenls
ENVIRONMENTAL & GEOTECHNICAL ENGINEERING NETWORK
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UPDATED GEOTECHNICAL STUDY
Proposed Structure
Parcel 19 of Parcel Map 28471-1
City of Temecula, County of Riverside, California
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Project Number: T1405-UGS
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Prepared for:
~n Tel-Com Development, Inc.
H'#'42111 Avenida Alvarado
Te-m?~LJla"Galifornia 92590
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Western Tel-Com Development, Inc.
Project Number: T1405-UGS
TABLE OF CONTENTS
Section Number and Title
Paqe
1.0
SITE/PROJECT DESCRIPTION .......................................................................... 1
SITE REVIEW .......................................................................................................2
2.1 Literature Research
2.2 Site Reconnaissance
2.0
3.0
EARTHWORK RECOMMENDATIONS.......................................... ...................... 3
3.1 General
3.2 Engineered Fill
FOUNDATION DESIGN RECOMMENDATIONS ................................................ 5
4.1 General
4.2 Foundation Size
4.3 Depth of Embedment
4.4 Bearing Capacity
4.5 Settlement
4.6 Lateral Capacity
SLAB-0N-GRADE RECOMMENDA TIONS......................................................... 7
5.1 General
5.2 Interior Slabs
5.3 Exterior Slabs
RETAINING WALL RECOMMENDATIONS ........................................................ 8
6.1 Earth Pressures
6.2 Foundation Design
6.3 Subdrain
6.4 Backfill
MISCELLANEOUS RECOMMENDATIONS ...................................................... 11
7.1 Pavement Design
7.2 Utility Trench Recommendations
7.3 Temporary Excavation or Cuts
7.4 Finish Lot Drainage
7.5 Planters
7.6 Supplemental Construction Observations and Testing
7.7 Pre-Grade Conference
CONSTRUCTION OBSERVATIONS AND TESTING ....................................... 15
CLOSURE
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Corporation
. Soil EngineeringandConsultingServices-EngineeringGeology. Compaction Testing
-Inspections- ConstruclionMaterialsTesling. Labor3loryTesling .PercolalionTesling
. Geology. Waler ResOlJrce Studies . Phase I & 11 Environmenlal Sire Assessments
,July 1,1998
ENVIRONMENTAL & GEOTECHNICAL ENGINEERING NETWORK
I Western Tel-Com Development, Inc.
,42111 Avenida Alvarado
Temecula, California 92590
I (909) 694-9355 1 FAX (909) 695-0805
I Attention:
Mr. Dave Marasco
1 Regarding:
ADDENDUM TO UPDATED GEOTECHNICAL STUDY
Proposed Structure
Parcel 19 of Parcel Map 28471-1
City of T emecula, County of Riverside, California
Project Number: T1405-UGS
1 References: 1.
EnGEN Corporation, Updated Geotechnical Study, Proposed Structure,
Parcel 19 of Parcel Map 28471-1, City of Temecula, County of Riverside,
California, Project Number: T1405-UGS, report dated April 20, 1998.
2. HLC Civil Engineering, Preliminary Grading Plan, Western Tel-Com
Development, Inc., Parcel 19 of Parcel Map 28471-1, plans undated.
3. Schaefer Dixon Associates, Geotechnical Mass Grading, Report No.2,
Parcel Map 21383 (Core I, Phase II), City of Temecula, County of Riverside,
California, report dated January 7, 1992.
1 Dear Mr. Marasco:
,At the request of the City of Temecula (via Hector Correa, Civil Engineer), we have been asked to
I provide additional pavement recommendations. These recommendations are presented below:
Pavement Section
Automobile Traffic
Truck T raffie
TI=5
TI=6
3" AC 17.5" A.B.
3"AC/11"A.B.
I Please call should you have any questions.
: Sincerely,
I EnGEN Corporation
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. Soil EngineeringandConsullingServices. EngineerlngGeology. CompadionTes ting
-Inspections. ConstrllClionMaterialsTesling. LaoolaloryTesling -PercolalionTesling
. Geology. Water Resource Studies e Phasel& II Environmental SileAssessments
,July 1,1998
ENVIRONMENTAL & GEOTECHNICAL ENGINEERING NETWORK
I Western Tel-Com Development, Inc.
,42111 Avenida Alvarado
Temecula, California 92590
I (909) 694-9355 1 FAX (909) 695-0805
, Attention:
Mr. Dave Marasco
I Regarding:
ADDENDUM TO UPDATED GEOTECHNICAL STUDY
Proposed Structure
Parcel 19 of Parcel Map 28471-1
City of Temecula, County of Riverside, California
Project Number: T1405-UGS
I References:
1.
EnGEN Corporation, Updated Geotechnical Study, Proposed Structure,
Parcel 19 of Parcel Map 28471-1, City of Temecula, County of Riverside,
California, Project Number: T1405-UGS, report dated April 20, 1998.
2. HLC Civil Engineering, Preliminary Grading Plan, Western Tel-Com
Development, Inc., Parcel 19 of Parcel Map 28471-1, plans undated.
3. Schaefer Dixon Associates, Geotechnical Mass Grading, Report No.2,
Parcel Map 21383 (Core I, Phase II), City of Temecula, County of Riverside,
California, report dated January 7, 1992.
I Dear Mr. Marasco:
,At the request of the City of Temecula (via Hector Correa, Civil Engineer), we have been asked to
I provide additional pavement recommendations. These recommendations are presented below:
Pavement Section
Automobile Traffic
Truck Traffic
TI=5
TI=6
3" AC 17.5" A.B.
3" AC /11" A.B.
I Please call should you have any questions.
. Thomas Dewey, CEG 1 5_,:d::::o,ts~
" I Principal Engineering Geologis["".":"",,
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CO!poration
. Soil Engineering and Consulting Services e Engine€ringGeoIO\lY. CompaclionTesting
elnsDeclions-ConslfuclionMaterialsTesling-LaboratoryTesting-PercoIationTesting
-Geology. Water ReSDurce Studies . Phase I &11 EnvironmenlalSiteAssessments
ENVIRONMENTAL & GEOTECHNICAL ENGINEERING NETWORK
IApril20, 1998
,Western Tel-C.om Development, Inc.
'42111 Avenida Alvarado
Temecula, California 92590
(909) 694-9355 I FAX (909) 695-0805
'Attention:
Mr. Dave Marasco
'Regarding:
UPDATED GEOTECHNICAL STUDY
Proposed Structure
Parcel 19 of Parcel Map 28471-1
City of Temecula, County of Riverside, California
Project Number: T1405-UGS
: References: 1.
HLC Civil Engineering, Preliminary Grading Plan, Western Tel-Com
Development, Inc., Parcel 19 of Parcel Map 28471-1, plans undated.
2.
Schaefer Dixon Associates, Geotechnical Mass Grading, Report
No.2, Parcel Map 21383 (Core I, Phase II), City of Temecula,
County of Riverside, California, report dated January 7, 1992.
:Dear Mr. Marasco:
Per your request and signed Proposal, a representative of this firm reviewed the
-referenced previous reports and visited the subject site on April 8, 1998, to visually
:observe and probe the surface within the subject lot, in order to update the report
referenced above.
11;0
SITE I PROJECT DESCRIPTION
The subject property consists of approximately 1 acre, located on the southeast
corner of Zevo Drive and Winchester Road, in the City of Temecula, California.
The proposed development will be a masonry, slab-on-grade structure.
The
remainder of the sitj3i'~consist of paved parking and associated hardscape and
imp(Q.y.emehts,
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Western Tel-Com Development, Inc.
Project Number: T1405-UGS
April 1998
Page 2
2.0
SITE REVIEW
2.1
Literature Research
Based .on the Referenced NO.2 report, the majority of the site is in engineered fill.
Pauba formation bedrock is exposed in the northwest corner of the site. Analyses
of the Referenced No. 1 plans and the plans from the Referenced No. 2 report
indicates that the majority of the proposed buildings' perimeter footings are to be
located in existing engineered fill areas. A small area of the proposed perimeter
footings (located at the northwest corner of the site) are to be located in Pauba
Formation bedrock areas.
Site Reconnaissance
Based on the site reconnaissance, it appears that no additional grading has been
performed since completion of grading as reported in the Referenced No.2 report.
No unusual geotechnical conditions were observed.
EARTHWORK RECOMMENDATIONS
Genera!: All organic debris should be removed from the site and not used in
proposed fills. Proposed grading involves minor cuts and fills of less than
approximately 1 foot to the existing grades in the proposed structure area.
Adequate foundation support can be provided by overexcavating the native
Pauba formation located in the northwest corner of the site. Overexcavation
should be performed so that a minimum thickness of two (2) feet of properly
engineered fill exists below the bottom of the proposed deepest footing
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Western Tel-Com Development, Inc.
Project Number: T1405-UGS
Apri/1998
Page 3
elevation.
Horizontal limits of overexcavation should extend a minimum
horizontal distance outside the sides of the footings equal to the depth of
overexcavation. Overexcavation should be performed so that engineered fill
exists under all footings. The existing areas of engineered fill should be scarified
12-inches, moisture conditioned and then properly recompacted to a minimum
relative compaction of 90%.
3.2
Enaineered Fill: All fill material, whether on-site material or import, should be
approved by the Project Geotechnical Engineer and/or his representative before
placement. All fill should be free from vegetation, organic material, and other
debris. Import fill should be no more expansive than the existing on-site material.
Approved fill material should be placed in horizontal lifts not exceeding 6.0 to 8.0-
inches dn thickness and watered or aerated to obtain near-optimum moisture
content (:t 2.0 percent of optimum). Each lift should be spread evenly and should
be thoroughly mixed to ensure uniformity of soil moisture. Structural fill should
meet a minimum relative compaction of 90 percent of maximum dry density based
upon ASTM 01557-78 (90) procedures. Moisture content of fill materials should
not vary more than 2.0 percent of optimum, unless approved by the Project
Geotechnical, Engineer.
FOUNDATION DESIGN RECOMMENDATIONS
General: Foundations for the proposed structure may consist of conventional
column footings and continuous wall footings founded upon properly compacted
fill. The ,recommendations presented in the subsequent paragraphs for foundation
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Project Number: T1405-UGS
April 1998
Page 4
design and construction are based on geotechnical characteristics and a low
expansion potential (EI=30) for the supporting soils and should not preclude more
restrictive structural requirements. The actual expansion potential will need to be
determined at completion of precise grading in order to verify the foundation
design recommendations made herein. The Structural Engineer for the project
should determine the actual footing widths and depths necessary to resist design
vertical, horizontal and uplift forces. The anticipated peak ground acceleration for
the site is 0.86g. If the structure is to be designed to the 1997 UBC the following
factors apply:
Seismic Source Type:
Type B fault
Soil Profile Type:
So (Engineered Fill)
Distance to Known Seismic Source:
Less than 2km
Foundation Size: Continuous footings should have a minimum width of 18 inches
and should be continuously reinforced with a minimum of two (2) No. 4 steel
reinforcing bars located near the top and two (2) No. 4 steel reinforcing bars
located 'near the bottom of the footings to minimize the effects of any slight
differential movements that may occur due to minor variations in the engineering
characteristics or any seasonal moisture change in the supporting soils. Column
footings !should have a minimum width of 18-inches by 18-inches and be suitably
reinforced based on structural requirements. A grade beam founded at the same
depths and reinforced as the adjacent footings should be provided across
doorway, garage entrances, or any other perimeter openings.
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Project Number: T1405-UGS
April 1998
Page 5
4.3
Depth of Embedment: Exterior and interior footings should extend to a minimum
depth of 18 inches below lowest adjacent finish grade in undisturbed, properly
compacted fill. Frost is not considered a design factor for foundations in the
Temecula, California, area as there is no significant frost penetration in the winter
months. Embedment of all footings on or near existing or planned slopes should
be determined by a minimum setback distance measured from the bottom outside
edge of the footing to the slope face according to the UBC and/or the City of
Temecula Building Codes.
Bearino Capacity: The recommended allowable bearing value for design of
continuous and column footings for dead plus live loads and founded in competent
silty sand (SM) fill material is 2,000 psf. The allowable bearing value may be
increased by 33.3 percent for short durations of live loading such as wind or
seismic forces.
Settlement: Footings designed according to a 2,000 psf bearing value and
founded in undisturbed, properly compacted fill are not expected to exceed a
maximum settlement of 0.75 inch or a differential settlement of 0.25 inch between
similarly'sized and loaded footings.
Lateral Capacity: Additional foundation design parameters based on competent
silty sand (SM) material for resistance to lateral forces are as follows:
Allowable Lateral Pressure (Equivalent Fluid Pressure)
Passive Case: 150 pcf - Fill Material
Allowable Coefficient of Friction: 0.30
The above values are allowable design values and have safety factors of at least
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Western Tel-Com Development, Inc.
Project Number. T1405-UGS
April 1998
Page 6
2.0 incorporated into them. For the calculation of passive earth resistance, the
upper 1.0 foot of material should be neglected unless confined by a concrete slab
or pavement.
SLAB-ON-GRADE RECOMMENDATIONS
General: The recommendations for concrete slabs, both interior and exterior, are
based upon an assumed low expansion potential for the supporting material. The
expansion potential of the slab subgrade areas should be verified at the
completion of any supplemental grading for the structure.
Interior Slabs: Interior concrete slabs-on-grade should be a minimum of 4.0
inches (5.0 inches if a forklift or other heavy equipment is used on the slab) actual
in thickness and be underlain by properly prepared subgrade. Minimum slab
reinforcement should consist of #3 reinforcing bars placed 24 inches on center in
both directions placed mid-depth in the slab or any equivalent system as might be
designed by the Project Structural Engineer. The concrete section and/or
reinforcing steel should be increased for excessive design floor loads or
anticipated concentrated loads. In areas where moisture sensitive floor coverings
are anticipated over the slab, we recommend the use of a polyethylene vapor
barrier a minimum of 6.0 mil in thickness be placed beneath the slab. The
moisture barrier should be overlapped or sealed at splices and covered by a 1.0 to
2.0-inch minimum layer of clean sand to aid in concrete curing and to minimize
potential punctures. If the moisture barrier is placed on crushed gravel material, it
is recommended that a minimum of 1.0 inch of clean sand or other approved
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Western Tel-Com Development, Inc.
Project Number: T1405-UGS
April 1998
Page 7
granular material be placed beneath the moisture barrier to prevent punctures from
angular gravel fragments and projections.
5.3
Exterior Slabs: All exterior concrete slabs cast on finish subgrade should be a
minimum of 4.0 inches nominal in thickness and be supported on soil that has
been compacted to a minimum of 90 percent relative compaction based on ASTM
D1557-78(90) procedures and moisture conditioned to at least 110 percent of
optimum moisture content to a minimum depth of 12 inches immediately before
pouring the slab. Reinforcing in the slabs and the use of a compacted sand or
gravel base beneath the slabs should be according to the current standards of the
City of Temecula.
RETAINING WALL RECOMMENDATIONS:
Earth Pressures: Retaining walls backfilled with non-expansive granular soil
(EI=O) or very low expansive potential materials (Expansion Index of 20 or less)
within a zone extending upward and away from the heel of the footing at a slope of
0.5:1 (horizontal to vertical) or flatter can be designed to resist the following static
lateral soil pressures:
Condition
Level Backfill
2:1 SlaDe
Active
30 pcf
45 pcf
At Rest
60 pet
The on-site materials may be used as backfill within the active I at-rest pressure
zone as defined above. Walls that are free to deflect 0.001 radian at the top
should be designed for the above-recommended active condition. Walls that are
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Project Number: T1405-UGS
April 1998
Page 8
not capable of this movement should be assumed rigid and designed for the at-
rest condition. The above values assume well-drained backfill and no buildup of
hydrostatic pressure. Surcharge loads, dead and/or live, acting on the backfill
within a horizontal distance behind the wall should also be should considered in
the design. Uniform surcharge pressures should be applied as an additional
uniform (rectangular) pressure distribution. The lateral earth pressure coefficient
for a uniform vertical surcharge load behind the wall is 0.50.
Foundation Desian: Retaining wall footings should be founded to the same
depths into properly compacted fill, or firm, competent, undisturbed, natural soil as
standard foundations and may be designed for the same average allowable
bearing value across the footing (as long as the resultant force is located in the
middle one-third of the footing), and with the same allowable static lateral bearing
pressure and allowable sliding resistance as previously recommended. When
using the allowable lateral pressure and allowable sliding resistance, a factor of
safety of 1.0 may be used. If ultimate values are used for design, an approximate
factor of safety (1.5) should be achieved. An approximate factor of safety of 1.5
should be achieved.
Subdrain: A subdrain system should be constructed behind and at the base of all
retaining walls to allow drainage and to prevent the buildup of excessive
hydrostatic pressures. Typical subdrains may include weep holes with a
continuous gravel gallery, perforated pipe surrounded by filter rock, or some other
approved system. Gravel galleries and/or filter rock, or another approved system.
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Project Number: T1405-UGS
April 1998
Page 9
Gravel galleries and/or filter rock, if not properly designed and graded for the on-
site and/or import materials, should be enclosed in a geotextile fabric such as
Mirafi 140N, Supac 4NP, or a suitable substitute in order to prevent infiltration of
fines and clogging of the system. The perforated pipes should be at least 4.0
inches in diameter. Pipe perforations should be places downward. Gravel filters
should have volume of at least 1.0 cubic foot per lineal foot of pipe. Subdrains
should maintain a positive flow gradient and have outlets that drain in a non-
erosive manner. In the case of Subdrains for basement walls, they need to empty
into a sump provided with a submersible pump activated by a change in the water
level.
:614 Backfill: Backfill directly behind retaining walls (if backfill width is less than 3 feet)
may consist of 0.5 - to 0.75-inch diameter, rounded to subrounded gravel enclosed
in a geotextile fabric such as Mirafi 140N, Supac 4NP, or a suitable substitute or a
clean sand (Sand Equivalent Value greater than 50) water jetted into place to
obtain proper compaction. If water jetting is used, the subdrain system should be
in place. Even if water jetting is used, the sand should be densified to a minimum
of 90 percent relative compaction. If the specified density is not obtained by water
jetting, mechanical methods will be required. If other types of soil or gravel are
used for backfill, mechanical compaction methods will be required to obtain a
relative compaction of at least 90 percent of maximum dry density. Backfill directly
behind retaining walls should not be compacted by wheel, track or other rolling by
heavy construction equipment unless the wall is designed for the surcharge
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Project Number: T1405-UGS
April 1998
Page 10
loading. If gravel, clean sand or other imported backfill is used behind retaining
walls, the upper 18-inches of backfill in unpaved areas should consist of typical on-
site material compacted to a minimum of 90 percent relative compaction in order to
prevent the influx of surface runoff into the granular backfill and into the subdrain
system, Maximum dry density and optimum moisture content for backfill materials
should be determined in accordance with ASTM 01557-78(90) procedures.
MISCELLANEOUS RECOMMENDATIONS
Pavement Desion: Preliminary pavement recommendations are presented based
on R-Value testing of soils obtained from the site, and an assumed future traffic
loading expressed in terms of a Traffic Index (TI).
Pavement sections have been determined in general accordance with CAL TRANS
design procedures based on a TI of 4.5 for automobile areas, a TI of 5.0 for truck
traffic areas, and an R-Value of 17. As a result, the project designer should
specify the appropriate pavement section for the various traffic areas as follows:
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Truck traffic
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3" AC / 8" AS
The project designer should choose the appropriate pavement section for the
anticipated traffic pattern and delineate the respective areas on the site plan.
Asphalt :concrete pavement materials should be as specified in Section 39 of the
current CAL TRANS Standard Specifications or a suitable equivalent. Aggregate
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Western Tel-Com Development, Inc.
Project Number: T1405-UGS
April 1998
Page 11
base should conform to Class 2 material as specified in Section 26-1.028 of the
current CAL TRANS Standard Specifications or a suitable equivalent. The
subgrade soil, including utility trench backfill, should be compacted to at least 90
percent relative compaction. The aggregate base material should be compacted
to at least 95 percent relative compaction. Maximum dry density and optimum
moisture content for subgrade and aggregate base materials should be
determined according to ASTM 01557-91 procedures. In dumpster pick-up areas,
and in areas where semi-trailers are to be parked on the pavement such that a
considerable load is transferred from small wheels, it is recommended that rigid
Portland Cement concrete pavement with a minimum thickness of 6.0 inches be
provided in these areas. This will provide for the proper distribution of loads to the
subgrade without causing deformation of the pavement surface. Special
consideration should also be given to areas where truck traffic will negotiate small
radius turns. Asphaltic concrete pavement in these areas should utilize stiffer
emulsions or the areas should be paved with Portland Cement concrete. If
pavement subgrade soils are prepared at the time of rough grading of the building
site and the areas are not paved immediately, additional observations and testing
will have to be performed before placing aggregate base material, asphaltic
concrete, or PCC pavement to locate areas that may have been damaged by
construction traffic, construction activities, and/or seasonal wetting and drying. In
the proposed pavement areas, soil samples should be obtained at the time the
subgrade is graded for R-Value testing according to California Test Method 301
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Western Tel-Com Development, Inc.
Project Number: T1405-UGS
April 1998
Page 12
procedures to verify the pavement design recommendations.
Utility Trench Recommendations: Utility trenches within the zone of influence of
foundations or under building floor slabs, hardscape, and/or pavement areas
should be backfilled with properly compacted soil. It is recommended that all utility
trenches excavated to depths of 5.0 feet or deeper be cut back to an inclination not
steeper than 1: 1 (horizontal to vertical) or be adequately shored during
construction. Where interior or exterior utility trenches are proposed parallel and/or
perpendicular to any building footing, the bottom of the trench should not be
located below a 1: 1 plane projected downward from the outside bottom edge of
the adjacent footing unless the utility lines are designed for the footing surcharge
loads. Backfill material should be placed in a lift thickness appropriate for the type
of backfill material and compaction equipment used. Backfill material should be
compacted to a minimum of 90 percent relative compaction by mechanical means.
Jetting of the. backfill material will not be considered a satisfactory method for
compaction. Maximum dry density and optimum moisture content for backfill
materialshould be determined according to ASTM 01557-78(90) procedures.
Temoorary Excavations Or Cuts: All temporary cuts and excavations should be
made in accordance with CAUOSHA minimum requirements for Type C soil. If
site restrictions require a different configuration, this office should be contacted to
develop construction recommendations.
Finish Lot Drainaae Recommendations: Finish lot surface gradients in unpaved
areas should be provided next to tops of slopes and buildings to direct surface
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Western Tel-Com Development, Inc.
Project Number: T1405-UGS
April 1998
Page 13
water away from foundations and slabs and from flowing over the tops of slopes.
The surface water should be directed toward suitable drainage facilities. Ponding
of surface water should not be allowed next to structures or on pavements. In
unpaved areas, a minimum positive gradient of 2.0 percent away from the
structures and tops of slopes for a minimum distance of 5.0 feet and a minimum of
1.0 percent pad drainage off the property in a non erosive manner should be
provided.
Planter Recommendations: Planters around the perimeter of the structure
should be designed to ensure that adequate drainage is maintained and minimal
irrigation water is allowed to percolate into the soils underlying the building.
Supplemental Construction Observations and Testina: Any subsequent
grading for development of the subject property should be performed under
engineering observation and testing performed by EnGEN Corporation.
Subsequent grading includes, but is not limited to, any additional overexcavation of
cut and/or cut/fill transitions, fill placement, and excavation of temporary and
permanent cut and fill slopes. In addition, EnGEN Corporation, should observe all
foundation excavations. Observations should be made prior to installation of
concrete forms and/or reinforcing steel so as to verify and/or modify, if necessary,
the conclusions and recommendations in this report.
Observations of
overexcavation cuts, fill placement, finish grading, utility or other trench backfill,
pavement subgrade and base course, retaining wall backfill, slab presaturation, or
other earthwork completed for the development of subject property should be
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Western Tel-Com Development, Inc.
Project Number. T140S-UGS
April 1998
Page 14
performed by EnGEN Corporation If any of the observations and testing to verify
site geotechnical conditions are not performed by EnGEN Corporation, liability for
the safety and performance of the development is limited to the actual portions of
the project observed and/or tested by EnGEN Corporation.
7.7
Pre-Gradina Conference: Before the start of any grading, a conference should
be held with the owner or an authorized representative, the contractor, the Project
Architect, the Project Civil Engineer, and the Project Geotechnical Engineer
present. The purpose of this meeting should be to clarify questions relating to the
intent of the supplemental grading recommendations and to verify that the project
specifications comply with the recommendations of this geotechnical engineering
report. Any special grading procedures and/or difficulties proposed by the
contractor can also be discussed at that time.
CONS"fRUCTION OBSERVATIONS AND TESTING: Supplemental grading of
the property should be performed under engineering observation and testing
performed by EnGEN Corporation. Supplemental grading includes, but is not
limited to, overexcavation cuts, fill placement, and excavation of temporary and
permanent cut and fill slopes. In addition, EnGEN Corporation should observe all
foundation excavations. Observations should be made before installation of
concrete forms and/or reinforcing steel to verify and/or modify.the conclusions and
recommendations in this report. Observations of overexcavation cuts, fill
placement, finish grading, utility or other trench backfill, hardscape subgrade,
pavement subgrade and base course, retaining wall backfill, slab presaturation, or
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Western Tel-Com Development, Inc.
Project Number: T1405-UGS
April 1998
Page 15
other earthwork completed for the subject development should be performed by
EnGEN Corporation if requested by the local building authority, or
owner/developer. If the observations and testing to verify site geotechnical
conditions are not performed by EnGEN Corporation, liability for the performance
of the development is limited to the actual portions of the project observed and/or
tested by EnGEN Corporation. If parties other than EnGEN Corporation are
engaged to perform soils and materials observations and testing, they must be
notified that they will be required to assume complete responsibility for the
geotechnical aspects of the project by concurring with the recommendations in this
report or providing alternative recommendations.
CLOSURE: This report has been prepared for use by the parties or project named
or described in this document. It mayor may not contain sufficient information for
other parties or purposes. In the event that changes in the assumed nature,
design, or location of the proposed structure and/or project as described in this
report, are planned, the conclusions and recommendations contained in this report
will not be considered valid unless the changes are reviewed and the conclusions
and recommendations of this report modified or verified in writing. This study was
conducted in general accordance with the applicable standards of our profession
and the accepted soil and foundation engineering principles and practices at the
time this report was prepared. No other warranty, implied or expressed beyond
the representations of this report, is made. Although every effort has been made
to obtain information regarding the geotechnical and subsurface conditions of the
site, limitations exist with respect to the knowledge of unknown regional or
localized off-site conditions that may have an impact at the site. The
recommendations presented in this report are valid as of the date of the report.
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Western Tel-Com Development, Inc.
Project Number: T1405-UGS
April 1998
Page 16
However, changes in the conditions of a property can occur with the passage of
time, whether they are due to natural processes or to the works of man on this
and/or adjacent properties. If conditions are observed or information becomes
available during the design and construction process that are not reflected in this
report, EnGEN Corporation should be notified so that supplemental evaluations
can be performed and the conclusions and recommendations presented in this
report can be modified or verified in writing. Changes in applicable or appropriate
standards of care or practice occur, whether they result from legislation or the
broadening of knowledge and experience. Accordingly, the conclusions and
recommendations presented in this report may be invalidated, wholly or in part, by
changes outside of the control of EnGEN Corporation, which occur in the future.
Thank you for the opportunity to provide our services. Often, because of design and
construction details which occur on a project, questions arise concerning the geotechnical
conditions on the site. If we can be of further service or you should have questions
regarding this report, please do not hesitate to contact this office at your convenience.
Because of our involvement in the project to date, we would be pleased to discuss
engineering testing and observation services that may be applicable on the project.
Respectfully submitted,
EnGEN Corporation
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Thomas Dewe, G 197
Principal Engineering Geologist
Expires 11-30-99
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Distribution: (4) Addressee
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