HomeMy WebLinkAboutTract Map 3883 Lot 495 Geotechnical Feasibility
I ~\. ';-~<.. Az:C.
I ~GEN COfl~oration
ENVIRONMENTAL & GEOTECHNICAL ENGINEERING NETWORK
I
I
I
I
I
I
I
I
I
I
I
I
3'fYlf~
. Soil EngineeringandConsullinqSe!vices-ErrgineeringGeology .COmpaclionTesling
-inspections.ConstruclionMaterialsTesting. LaboraloryTeslill\lePercolalionTesting
. Geology. Water Resource Studies . Phase i & II Environmental Site Assessments
GEOTECHNICAL FEASIBILITY STUDY
Staus Residence
Assessor's Parcel Number: 919-323-004
Lot 495, Tract 3883, Del Rey Road
City of T emecula, County of Riverside, California
Project Number: T2944-GFS
August 31,2003
Prepared for:
RECErVED
SEP 1 6 2003
I
I ____
.r. ~.,'
//,'
Mr. Gerald Staus
31354 Club Vista Lane
Bonsall, California 92003
CITY OF TEMECULA
ENGINEERING DEPARTMENT
\.
-' -
, '
" -- !
/ __ I
- ' -
, , -
r- __ I
, ,
, '
, ,
'/ "'- /,1 "-
. I -' \ _ _ _ \ /
'- ,
, .
- ,
'- ,
- '
, - -
-- \ -' '-,
- '
- '
," \- -- \.
,
,- - - \
I I \ I ~ I, \ / I I \ I ~'
-:::::'=~";;"t::f.,;;;;:;:- ~""o~~~::~~::s::;
;;;';;;",m",,,,Q.!I, ~~I;l~ 0
~"^",,'=-""~l1'@RrGQuJli~ID-
~~'SiJ~~~:twi'~\:,~~'~':;'~"~~-:'-'
. -~ -- -,- -.. -- ,.
.
.
I.
.
I
I
I
.
I
I
I
I
I
I
I
I
I
I
I
I
Mr. Gerald Staus
Project Number: T2944-GFS
TABLE OF CONTENTS
Section Number and Title
Page
1.0 SITE/PROJECT DESCRiPTION......................................................................................1
1.1 Site Description ....................................................................................................1
1.2 Project Description ...............................................................................................2
ZO RN~NGS ..............................................................................................2
2.1 Site Review................................. ......... ........ ......... ...... ......... ......... ...... ... ... ........ .... 2
2.2 Laboratory Testing....." "."".""""""".......... ......"............" ..""."....."..."..."... "".. 2
2.2.1 General "".""".."................. ."....."""..". .......... .."".... ..... ""..."." ...... ..... 2
2.2.2 Classification....................."........"......................................................... 2
2.2.3 Maximum Dry Density/Optimum Moisture Content Relationship TesL.2
2.2,4 Expansion Potential..."........................................................................... 3
2.2.5 Soluble Sulfates...................................................................................... 3
2.2.6 Direct Shear TesL......."...".""""."".............""w."... .."" ""........ ."""" 3
2.3 Excavation Characteristics................................................................................... 3
3.0 ENGINEERING GEOLOGY/SEISMICITY ......".........""..................."........"...""..".."",,4
3.1 Geologic Setting ".....".................".."""."........"......""...."".."."."......................4
3.2 Seismic Hazards................................................................................................... 4
3.2.1 Surface Fault Rupture ........"".""""......"."""."....".."""""......"."..."..,4
3.2.2 Liquefaction..................."....................................................................... 4
3.2.3 Seismically-Induced Landsliding.. ....... ........ .............. ... ... ... ... '" ... ..... ... .... 4
3.2,4 Seismically-Induced Flooding, Seiches and Tsunamis."."."."...."".".".5
3.3 Earth Materials """..... ...........". .."."" ........ .....". """. ........." ""..... ..""."... ......".".5
3.3.1 Colluvium ...""""""."""..."........"."",,.. ........ .."......... .."" ..".. "'" """ ...... 5
3.3.2 Pauba Formation ......... ......".."."". ............""."... ......"" """"......."........ 5
4.0 EARTHWORK RECOMMENDATIONS. ................................. ....... ... ............ .... ........... .... 5
4.1 All Areas ."........".......".""".""....".........""....".........""".""",,.........,,....."....."...5
4.2 Oversize Materia1...... .... ....... .... .... ................. ........ .... .... ... .... ...... ...... .... '" ..... ... ...... 7
4.3 Structural Fill.... ....... ................."......".... ........... ................... ........ ........ .... ..... ........7
5.0 SLOPE STABILITY - GENERAL...."..........."".".".......""."""......."."......"""."........." 7
5.1 Fill Slopes ...".".....""".............""".."..".............."........."."".......".".,,....."......". 7
5.2 Cut Slopes ...".."""."."..".............""..""..".."..."."""............."..",,........."."....... 7
6.0 CONCLUSIONS AND RECOMMENDATIONS .."""."......"..""..."."..".""."....."".".".,,8
6.1 Foundation Design Recommendations ".""""...".".."."".".""""""......""""....,,8
6.1.1 Foundation Size............"".".""........."".""."...."""...""......"""........"" 8
6.1.2 Depth of Embedment ."..""...".........".".""......"."."..".."""."...""."."" 8
6.1.3 Bearing Capacity ..".."".""............""""""..."...".................."...."."..",, 8
6.1,4 Seismic Design Parameters ."""""......."....""."."."""....""......,,.......... 9
6.1.5 Settlement ................."..."."."........""""""............"..........."........."...... 9
6.2 Lateral Capacity".."......... ....... ".".""..,,"...... .."...."" '"'''''''''''''''''' .""...... ."......" 9
6.3 Slab-on-Grade Recommendations.. .....".. ..".." ...."" ............................".. ...". .."" 9
6,4 Exterior Slabs ......."...."""."....".............""........."."."""......."..,,........,,.........".10
EnGEN Corporation
7--
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Mr. Gerald Staus
Project Number: T2944-GFS
TABLE OF CONTENTS IContinued)
Section Number and Title
Page
7.0 RETAINING WALL RECOMMENDATIONS ...............................................................10
7.1 Earth Pressures..................................................................................................10
7.2 Retaining Wall Design ...........H...........................................................................11
7.3 Subdrain .............................................................................................'''''''''''''''' 11
7,4 Backfill ........................ ................... .......... ............. ....... ....................... ................ 11
8.0 MISCELLANEOUS RECOMMENDATIONS ...............................................................12
8.1 Utility Trench Recommendations........................................................................12
8.2 Finish Lot Drainage Recommendations ..............................:..............................12
8.3 Planter Recommendations ........................mm................................................... 13
8,4 Supplemental Construction Observations and Testing ...................................... 13
8.5 Plan Review...............................m........m...........................................................13
8.6 Pre-Bid Conference ............................ ............... ............ ............. ....... ................. 14
8.7 Pre-Grading Conference ....................................................................................14
9.0 CLOSURE.... '''''''''' ......... ....... ............... ................. ......................... .............. ...... ....... 14
APPENDIX:
TECHNICAL REFERENCES
LABORATORY TEST RESULTS
DRAWINGS
~
I r'\ ,,~'>-/'
I ~~~GEN
I
I
I
I
I
I
I
I
I
I
I
I
I
I
-Soil EnllineerinllandConsultinll Services-EngineerinllGeology- Compaction Tesling
-lnspections.ConstrllCtionMaterialsTesting elaboraloryTesting-PercolallonTesling
. GeoIO!lY. Water Resource Sludles . Phase I &11 Environmental SlleAssessments
Coq:~oration
ENVIRONMENTAL & GEOTECHNICAL ENGINEERING NETWORK
August 31,2003
Mr. Gerald Staus
31354 Club Vista Lane
Bonsall, California 92003
(760) 631-7616
Regarding:
GEOTECHNICAL FEASIBILITY STUDY
Staus Residence
Assessor's Parcel Number: 919-323-004
Lot 495, Tract 3883, Del Rey Road
City of Temecula, County of Riverside, California
Project Number: T2944-GFS
Reference:
1.
Bratene Construction and Engineering, Precise Grading Plan, Staus
Residence, Del Rey Road, Temecula, California, Scale: 1" = 20', plan dated
May 7, 2003.
Dear Mr. Staus:
In accordance with your request and signed authorization, a representative of this firm has visited
the subject site on August 22, 2003, to visually observe the surficial conditions of the subject lot and
to collect samples of representative surficial site materials. Laboratory testing was performed on
these samples. Test results and preliminary foundation recommendations for the construction and
grading of the proposed development are provided. It is our understanding that cut and fill type
grading will take place for the proposed structural development Based on this firm's experience
with this type of project, our understanding of the regional geologic conditions surrounding the site,
and our review of in-house maps, published and unpublished reports, deeper subsurface
exploration was not considered necessary. However, in lieu of subsurface exploration, additional
grading beyond that anticipated in this report may be necessary depending on exposed conditions
encountered during grading.
1.0
1.1
" ,
" ,- - - \--
, '..
, '
.:: '- ~ -- I
SITE/PROJECT DESCRIPTION
Site Description: The subject site consists of approximately 0.82-acres with vertical
topographic relief of approximately 35-feet The site is located southeast of the
intersection of Del Rey Road and Avenida Buena Suerte in the City of Temecula, County
of Riverside, California. The topography slopes towards the western portion of the site
where a small drainage course bisects the property. Overall site drainage is through
sheet flow towards the west At the time of our site reconnaissance the site had been
-',
recently disked. No struct'yres were located on-site. The parcels to the northeast and
southeast are .presently vacant The other adjacent parcels are developed with single
family type residential structures.
. I'
.' " rr
I , \ _ _ _ \ ~
/ '- ,,1_'
- '
. I ,
, .
I'
- I ,
.... ,- --
\ - - - \
, -
, "
~" ~ - -_ I
, "
'-" ,,__ I
"" __ I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Mr. Gerald Staus
Project Number: T2944-GFS
August 2003
Page 2
1.2 Project Description: Based on our review of the referenced grading plan and structural
foundation plan, the proposed development will consist of a one to two-story single family
wood-framed home with slab-on-grade foundations. The maximum amount of cut will be
approximately 13-feet, and the maximum depth of fill will be approximately 9.5-feet. All
cut and fill slopes are planned to be constructed at a ratio of 2:1, horizontal to vertical, or
flatter. We are providing general grading and minimum footing recommendations for the
proposed development. We have reviewed the proposed foundation plan (undated) and
have determined that it conforms to the recommendations of this report. Any changes to
the plan should be reviewed by this office so that additional recommendations can be
made, if necessary.
2.0 FINDINGS
2.1 Site Review: Based on our site visit, it appears that colluvium and Pauba Formation
bedrock underlie the site. Colluvium mantles the bedrock throughout the site. Since no
deeper subsurface exploration was performed for this investigation, the thickness and
condition of the colluvium is unknown.
2.2 Laboratorv Testing:
2.2.1 General: The results of laboratory tests performed on samples of earth material obtained
during the site visit are presented in the Appendix. Following is a listing and brief
explanation of the laboratory tests performed. The samples obtained during the field study
will be discarded 30 days after the date of this report. This office should be notified
immediately if retention of samples will be needed beyond 30 days.
2.2.2 Classification: The field classification of soil materials encountered during our site visit
were verified in the laboratory in general accordance with the Unified Soils Classification
System, ASTM 0 2488-93, Standard Practice for Determination and Identification of Soils
(Visual-Manual Procedures).
2.2.3 Maximum Dry Density/Optimum Moisture Content Relationship Test: Maximum dry
density/optimum moisture content relationship determinations were performed on
samples of near-surface earth material in general accordance with ASTM 1557-00
procedures using a 4.0-inch diameter mold. Samples were prepared at various moisture
contents and compacted in five (5) layers using a 10-pound weight dropping 18-inches
-s
EnGEN Corporation
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Mr. Gerald Staus
Project Number: T2944-GFS
August 2003
Page 3
and with 25 blows per layer. A plot of the compacted dry density versus the moisture
content of the specimens is constructed and the maximum dry density and optimum
moisture content determined from the plot.
2.2.4 EXDansion Potential: Preliminary Expansion Index testing was performed, yielding an
Expansion Index (EI) of 2. This is classified as a very low expansion potential. Import soils
or soils used near finish grade may have a different EL At the conclusion of grading, our
firm should perform sampling and Expansion Index testing of the soils at final pad grade as
well as at footing grade. Those results should be forwarded and incorporated into the final
foundation design by the Project Structural Engineer. The Project Structural Engineer
should determine the actual footing width and depth to resist design vertical, horizontal, and
uplift forces based on the final Expansion Index test results. The recommendations for
concrete slab-on-grade reinforcement and thickness, both interior and exterior, excluding
PCC pavement, should be provided by the Project Structural Engineer based upon the
information provided at the conclusion of grading, and considering the expansion potential
for the supporting material as determined by Table 18-1-B of the Uniform Building Code.
2.2.5 Soluble Sulfates: Samples of near-surface earth material were obtained for soluble sulfate
testing for the site. The concentration of soluble sulfates was determined in general
conformance with California Test Method 417 procedures. The test results indicate that
water-soluble sulfates were not detected in excess of the reportable detection limit As a
result, sulfate resistant concrete is not necessary.
2.2.6 Direct Shear Test: Direct shear tests were performed on select samples of near-surface
earth material in general accordance with ASTM 0 3080-98 procedures. The shear
machine is of the constant strain type. The shear machine is designed to receive a 1.0-inch
high, 2.416-inch diameter ring sample. Specimens from the sample were sheared at
various pressures normal to the face of the specimens. The specimens were tested in a
submerged condition. The maximum shear stresses were plotted versus the normal
confining stresses to determine the shear strength (cohesion and angle of internal friction).
2.3 Excavation Characteristics: Excavation and trenching within the colluvium and bedrock is
anticipated to be relatively easy with conventional grading equipment.
'"
EnGEN Corporation
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Mr. Gerald Staus
Project Number: T2944-GFS
August 2003
Page 4
3.0 ENGINEERING GEOLOGY/SEISMICITY
3.1 Geologic Setting: The site is located in the Northern Peninsular Range on the southern
sector of the structural unit known as the Perris Block. The Perris Block is bounded on the
northeast by the San Jacinto Fault Zone, on the southwest by the Elsinore Fault Zone, and
on the north by the Cucamonga Fault Zone. The southern boundary of the Perris Block is
not as distinct, but is believed to coincide with a complex group of faults trending southeast
from the Murrieta, California area (Kennedy, 1977 and Mann, 1955). The Peninsular Range
is characterized by large Mesozoic age intrusive rock masses flanked by volcanic,
metasedimentary, and sedimentary rocks. Various thicknesses of colluvial/alluvial
sediments derived from the erosion of the elevated portions of the region fill the low-lying
areas. Colluvium and Pauba Formation bedrock underlie the site. The earth materials
encountered on the subject site are described in more detail in subsequent section of this
report.
3.2 Seismic Hazards: Because the proposed development is located in tectonically active
southern California, it will likely experience some effects from earthquakes. The type or
severity of seismic hazards affecting the site is mainly dependent upon the distance to the
causative fault, the intensity of the seismic event, and the soil characteristics. The seismic
hazard may be primary, such as surface rupture and/or ground shaking, or secondary, such
as liquefaction or dynamic settlement
3.2.1 Surface Fault Rupture: The site is not located within a State desi9nated Alquist-Priolo
Earthquake Zone. No known active faults exist on the subject site. No faulting was
obseNed during our site reconnaissance. The nearest State designated active fault is the
Elsinore Fault (Temecula Segment), located approximately 1.8 miles (2.9 Km) from the
subject site. This conclusion is based on literature review (references) and EnGEN
Corporation's site visit Accordingly, the potential for fault surface rupture on the site is very
unlikely.
3.2.2 Liquefaction: Based on the earthwork recommendations in Section 4.0 and the dense
nature of the underlying bedrock, the potential for hazards associated with liquefaction are
considered very low.
3.2.3 Seismically Induced Landsliding: Due to the overall low topographic relief conditions of
the site, the probability of seismically induced land sliding is considered low.
7
EnGEN Corporation
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Mr. Gerald staus
Project Number: T2944-GFS
August 2003
Page 5
3.2.4 Seismically Induced Flooding. Seiches and Tsunamis: Due to the absence of a
confined body of water in the immediate vicinity of the project site, the possibility of
seismically induced flooding or seiches is considered nil. Due to the large distance of the
project site to the Pacific Ocean, the possibility for seismically induced tsunamis to impact
the site is considered nil.
3.3 Earth Materials
3.3.1 Colluvium: Colluvium mantles the bedrock across the entire site. The colluvium consists
of brown porous clayey silty sand. Since no deeper subsurface exploration was performed
for this investigation, the depth and condition of the colluvium is unknown. Based on our
experience in the area and the exposed road cuts and bedrock outcrops near the site, we
anticipate the colluvium in the proposed fill areas to range in thickness from 2 to 3-feet with
local pockets up to 5-feet thick in the lower elevations of the site.
3.3.2 Pauba Formation: Pauba Formation was observed during our site reconnaissance.
Pauba Formation was observed in the road cuts and bedrock outcrops in the immediate site
vicinity, as well as on similar projects in the area. Regional geologic maps (Kennedy, 1977)
indicate that the sandstone member of the Pauba Formation underlies the site. Regional
bedding orientations are N710W with a dip to the northeast of 3 degrees. Pauba
Formation at the site constitutes bedrock.
4.0 EARTHWORK RECOMMENDATIONS
4.1 All Areas:
1. All vegetation should be removed from areas to be graded and not used in fills.
2. All colluvium and weathered bedrock should be removed from proposed fill, structural
and hardscape areas, cleared of any debris, and may then be placed back as
engineered fill. Based on our experience in this area of southwest Riverside County,
depths of removals are anticipated to be two (2) to three (3) feet below existing grades
in the upper colluvial areas, and up to five (5) feet below existing grades in the natural
drainage course. Deeper removals may be required depending upon exposed
conditions encountered.
~
EnGEN Corporation
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Mr. Gerald Staus
Project Number: T2944-GFS
August 2003
Page 6
3. All exposed removal and overexcavation bottoms should be inspected by the
Geotechnical Engineer's representative prior to placement of any fill. Bedrock bottoms
should be probed to verify competency.
4. The approved exposed bottoms of all removal areas should be scarified 12-inches,
brought to near optimum moisture content, and compacted to a minimum of 90 percent
relative compaction before placement of fill. Maximum dry density and optimum
moisture content for compacted materials should be determined according to ASTM D
1557-00 procedures.
5. Based on our review of the referenced grading plan, the location of the building
footprint appears to span across the cutlfill transition. The cut and shallow fill portion of
the structure area should be overexcavated. The depth of overexcavation should be
six (6) feet, or one-half of the depth of the deepest fill, below proposed grade,
whichever is greater. The horizontal extent of the overexcavation should be a
minimum of six (6) feet outside of the perimeter footings. As an alternative to
overexcavation, footings may be deepened so that they are founded a minimum of 1-
foot into unweathered bedrock.
6. A keyway excavated into bedrock should be constructed at the toe of all fill slopes that
are proposed on natural grades of 5: 1 (horizontal to vertical) or steeper. Keyways
should be a minimum of twelve (12) feet wide (equipment width) and tilted a minimum
of 2 percent into the hillside. A series of level benches should be constructed into
competent bedrock or competent alluvium on natural grades of 5:1 (horizontal to
vertical) or steeper prior to placing fill.
7. All fill and cut slopes should be constructed at slope ratios no steeper than 2: 1
(horizontal to vertical). All cut slopes should be inspected by the Project Geologist to
verify stability. Cut slopes exposing significant amounts of colluvium may be unstable.
Unstable cut slopes may require flattening or buttressing.
8. Every effort should be made to keep expansive soils, if any, outside the proposed
building footprint Final verification of the expansive character of the soils used to
construct the building area should be determined at the conclusion of grading by
performing an expansion test on a representative soil sample retrieved from the
EnGEN Corporation
~
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
5.0
5.1
5.2
Mr. Gerald Staus
Project Number: T2944-GFS
August 2003
Page 7
finished pad area subgrade and at footing grade so that final foundation design
recommendations can be established.
4.2
Oversize Material: Oversized material is defined as rock or other irreducible material
with a maximum dimension greater than 12-inches. Oversize material is not anticipated
to be encountered during grading of the proposed development Oversize material shall
not be buried or placed in fill unless location, materials, and placement methods are
specifically accepted by the Project Geotechnical Engineer.
4.3
Structural Fill: All fill material, whether on-site material or import, should be accepted 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, unless approved by the Project
Geotechnical Engineer. Approved fill material should be placed in horizontal lifts not
exceeding 6.0 to 8.0-inches in thickness, and watered or aerated to obtain near-optimum
moisture content (within 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 0
1557-00 procedures. Moisture content of fill materials should not vary more than 2.0
percent of optimum, unless approved by the Project Geotechnical Engineer.
SLOPE STABILITY - GENERAL
Fill Slopes: It is our opinion that the fill slopes, as planned, will possess gross and surficial
stability in excess of generally accepted minimum engineering criteria (Factor of Safety at
least 1.5) and are suitable for their intended purpose, provided that proper slope
maintenance procedures are maintained. These procedures include but are not limited to
installation and maintenance of drainage devices and planting of slope faces to protect from
erosion in accordance with County of Riverside Grading Codes.
Cut Slopes: It is our opinion that the cut slopes, as planned, will possess gross and
surficial stability in excess of generally accepted minimum engineering criteria (Factor of
Safety at least 1.5) and are suitable for their intended purpose, provided that proper slope
maintenance procedures are maintained. These procedures include but are not limited to
installation and maintenance of drainage devices and planting of slope faces to protect from
EnGEN Corporation
\0
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Mr. Gerald staus
Project Number: T2944-GFS
August 2003
Page 8
erosion in accordance with County of Riverside Grading Codes. The maximum height of
cut slope covered in this report is thirteen (13) feet
6.0 CONCLUSIONS AND RECOMMENDATIONS
6.1 Foundation Design Recommendations: Foundations for the proposed structures may
consist of conventional column footings and continuous wall footings founded in properly
compacted fill or unweathered bedrock, but not a combination of both. The
recommendations presented in the subsequent paragraphs for foundation design and
construction are based on geotechnical characteristics and upon an assumed very low
expansion potential for the supporting soils and should not preclude more restrictive
structural requirements. The Structural Engineer for the project should determine the
actual footing width and depth in accordance with the latest edition of the California
Building Code to resist design vertical, horizontal, and uplift forces and should either
verify or amend the design based on final expansion testing at the completion of grading.
6.1.1 Foundation Size: Continuous footings should have a minimum width of 12-inches.
Continuous footings should be continuously reinforced with a minimum of one (1) NO.4
steel reinforcing bar located near the top and one (1) NO.4 steel reinforcing bar located
near the bottom of the footings to minimize the effects of slight differential movements which
may occur due to minor variations in the engineering characteristics or 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 the same as the adjacent footings, should be
provided across doorway and garage entrances.
6.1.2 Depth of Embedment: Exterior and interior footings founded in properly compacted fill
should extend to a minimum depth of 12-inches for single story structures and 18-inches
for two story structures below lowest adjacent finish grade.
6.1.3 Bearing Capacity: Provided the recommendations for site earth work, minimum footing
width, and minimum depth of embedment for footings are incorporated into the project
design and construction, the allowable bearing value for design of continuous and column
footings for the total dead plus frequently-applied live loads is 2,000 psf for footings in
properly compacted fill and 2,500 psf for unweathered bedrock. The allowable bearing
EnGEN Corporation
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Mr. Gerald Staus
Project Number: T2944-GFS
August 2003
Page 9
value has a Factor of Safety of at least 3.0 and may be increased by 33.3 percent for
short durations of live and/or dynamic loading such as wind or seismic forces.
6.1.4 Seismic Design Parameters: The following seismic parameters apply:
Name of Fault: Elsinore Fault (Temecula Segment)
Type of Fault: Type B Fault
Closest Distance to Known Fault: Less than 5 Km (2.9 Km)
Soil Profile Type: SD
6.1.5 Settlement: Footings designed according to the recommended bearing values and the
maximum assumed wall and column loads are not expected to exceed a maximum
settlement of 0.50-inch or a differential settlement of 0.25-inch in properly compacted fill
under static load conditions.
6.2 Lateral Capacity: Additional foundation design parameters based on compacted fill for
resistance to static lateral forces, are as follows:
Allowable Lateral Pressure (Equivalent Fluid Pressure), Passive Case:
Compacted Fill - 250 pcf
Unweathered Bedrock - 350 pcf
Allowable Coefficient of Friction:
Compacted Fill - 0.40
Lateral load resistance may be developed by a combination of friction acting on the base
of foundations and slabs and passive earth pressure developed on the sides of the
footings and stem walls below grade when in contact with undisturbed, properly,
compacted fill material. The above values are allowable design values and may be used
in combination without reduction in evaluating the resistance to lateral loads. The
allowable values may be increased by 33.3 percent for short durations of live and/or
dynamic loading, such as wind or seismic forces. 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. The maximum recommended allowable passive pressure is
5.0 times the recommended design value.
6.3 Slab-on-Grade Recommendations: The recommendations for concrete slabs, both
interior and exterior, excluding PCC pavement, are based upon the anticipated building
usage and upon a very low expansion potential for the suPportin9 material as determined
by Chapter 18 of the California Building Code. Concrete slabs should be designed to
EnGEN Corporation
\\
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
7.0
7.1
Mr. Gerald Staus
Project Number: T2944-GFS
August 2003
Page 10
minimize cracking as a result of shrinkage. Joints (isolation, contraction, and
construction) should be placed in accordance with the American Concrete Institute (ACI)
guidelines. Special precautions should be taken during placement and curing of all
concrete slabs. Excessive slump (high water/cement ratio) of the concrete and/or
improper curing procedures used during either hot or cold weather conditions could result
in excessive shrinkage, cracking, or curling in the slabs. It is recommended that all
concrete proportioning, placement, and curing be performed in accordance with ACI
recommendations and procedures. Slab-on-grade reinforcement and thickness should be
provided by the structural engineer based on structural considerations, but as a minimum,
it is recommended that concrete floor slabs be at least 4-inches nominal in thickness and
reinforced with at least No. 3 reinforcing bars placed 24-inches on center, both ways,
placed at mid-height of the slab cross-section. Final expansion testing at completion of
grading could cause a change in the slab-on-grade recommendations. In areas where
moisture sensitive floor coverings are anticipated over the slab, we recommend the use of
a polyethylene vapor barrier with a minimum of a 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-inch minimum layer of clean, moist (not saturated) sand to aid in curing and to
minimize potential punctures.
64
Exterior Slabs: All exterior concrete slabs cast on finish subgrade (patios, sidewalks,
etc., with the exception of PCC pavement) should be a minimum of 4-inches nominal in
thickness. Reinforcing in the slabs and the use of a compacted sand or gravel base
beneath the slabs should be according to the current local standards. Subgrade soils
should be moisture conditioned to at least optimum moisture content to a depth of
12-inches immediately before placing the concrete.
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 (horizontai to vertical) or
flatter can be designed to resist the following static lateral soil pressures:
Condition Level Backfill 2:1 Slope
Active 30 Dcf 45 pet
At Rest 60 pcf --
EnGEN Corporation
\2..
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
7.3
7,4
Mr. Gerald Staus
Project Number: T2944-GFS
AU9ust 2003
Page 11
Further expansion testing of potential backfill material should be performed at the time of
retaining wall construction to determine suitability. Walls that are free to deflect 0.01 radian
at the top may be designed for the above-recommended active condition. Walls that are 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 behind the wall should also be
considered in the design.
7.2
Retaining Wall Design: 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 an allowable bearing value of 2,000 psf when founded in
compacted fill, and 2,500 psf when founded in unweathered bedrock (as long as the
resultant force is located in the middle one-third of the footing). Allowable static lateral
bearing pressure of 250 psf/ft may be used in compacted fill and 350 psf/ft may be used in
unweathered bedrock. An allowable sliding resistance coefficient of friction of 0.35 is
applicable for both fill and bedrock. When using the allowable lateral pressure and
allowable sliding resistance, a Factor of Safety of 1.5 should be achieved.
Subdrain: A subdrain system should be constructed behind and at the base of retaining
walls equal to or in excess of 5-feet in height to allow drainage and to prevent the buildup of
excessive hydrostatic pressures. 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 placed downward. Gravel filters should have volume
of at least 1.0 cubic foot per lineal foot of pipe. For retaining walls with an overall height of
less than 5-feet, subdrains may include weep holes with a continuous gravel gallery,
perforated pipe surrounded by filter rock, or some other approved system. Subdrains
should maintain a positive flow gradient and have outlets that drain in a non-erosive
manner.
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
EnGEN Corporation
\2::>
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
8.2
Mr. Gerald staus
Project Number: T2944-GFS
August 2003
Page 12
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
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 0 1557-00 procedures.
8.0
MISCELLANEOUS RECOMMENDATIONS
8.1
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 material should be
determined according to A$TM 0 1557-00 procedures.
Finish Lot Drainage Recommendations: Finish lot surface gradients in unpaved areas
should be provided next to tops of slopes and buildings to direct surface water away from
EnGEN Corporation
\-it
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
8.5
Mr. Gerald Staus
Project Number: T2944-GFS
August 2003
Page 13
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 4.0 percent away from the structures and tops of slopes for a minimum distance of 3.0-
feet and a minimum of 1.0 percent pad drainage off the property in a non-erosive manner
should be provided.
8.3
Planter Recommendations: Planters around the perimeter of the structure should be
designed with proper surface slope to ensure Jhat adequate drainage is maintained and
minimal irrigation water is allowed to percolate into the soils underlying the building.
8,4
Suoplemental Construction Observations and Testing: 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 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 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.
Plan Review: Subsequent to formulation of final plans and specifications for the project but
before bids for construction are requested, grading and foundation plans for the proposed
development should be reviewed by EnGEN Corporation to verify compatibility with site
geotechnical conditions and conformance with the recommendations contained in this
report. If EnGEN Corporation is not accorded the opportunity to make the recommended
review, we will assume no responsibility for miSinterpretation of the recommendations
presented in this report.
EnGEN Corporation
\6"
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
8.7
9.0
Mr. Gerald staus
Project Number: T2944-GFS
August 2003
Page 14
8.6
Pre-Bid Conference: It is recommended that a pre-bid conference be held with the owner
or an authorized representative, the Project Architect, the Project Civil Engineer, the Project
Geotechnical Engineer and the proposed contractors present This conference will provide
continuity in the bidding process and clarify questions relative to the supplemental grading
and construction requirements of the project.
Pre-Grading 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.
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 are 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. 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
EnGEN Corporation
\(;,
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Mr. Gerald Staus
Project Number: T2944-GFS
August 2003
Page 15
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 should you 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.
FILE: EnGE eporting\LGS\T2944-GFS Gerald Staus, Geotechnical Feasibility
EnGEN Corporation
\1
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
15.
16.
Mr. Gerald Staus
Project Number: T2944-GFS
Appendix Page 1
TECHNICAL REFERENCES
1.
California Building Code, 1998, State of California, California Code of Regulations, Title
24, 1998, California Building Code: International Conference of Building Officials and
California Building Standards Commission, 3 Volumes.
California ~ivision of Mines and Geology, CD-ROM 2000-003 Official Map of Alquist-Priolo
Earthquake Fault Zones, Murrieta Quadrangle, 1990.
California ~ivision of Mines and Geology, 1997, Guidelines for Evaluating and Mitigating
Seismic Hazards in California, Special Publication 117.
Hart, Earl W., and Bryant, William A, Revised 1997, Fault-Rupture Hazard Zones in
California, Alquist-Priolo Earthquake Fault Zoning Act with Index to Earthquake Fault Zone
Maps: State of California, Department of Conservation, Division of Mines and Geology, 38
Pages reviewed at the California Geological Survey's web page: hltp://www.consrv.ca.gov
/cgs/rghm/ap/ Mapjndex/F4E.htm#SW
Jennings, CW., 1975, Fault Map of California with Locations of Volcanoes, Thermal
Springs and Thermal Wells, 1 :750,000: California Division of Mines and Geology, Geologic
Data Map NO.1.
Jennings, C.W., 1985, An explanatory text to accompany the 1 :750,000 scale Fault and
Geologic Maps of California: California Division of Mines and Geology, Bulletin 201, 197p.,
2 plates.
Kennedy, M.P., 1977, Recency and Character of Faulting Along the Elsinore Fault Zone in
Southern Riverside County. California: California Division of Mines and Geology, Special
Report 131,12 p., 1 plate, scale 1:24,000.
Mann, J.F., Jr., October 1955, Geology of a Portion of the Elsinore Fault Zone, California:
State of California, Department of Natural Resources, ~ivision of Mines. Special Report
43.
Morton, O. M., 1999, Preliminary Digital Geologic Map of the Santa Ana 30' x 60'
Quadrangle, Southern California, version 1.0., Open File Report 99-172,
Riverside, County of, 2000, Transportation and Land Management Agency, Technical
Guidelines for Review of Geotechnical and Geologic Reports, 2000 Edition.
Riverside, County of, 1978, Seismic Safety/Safety Element Policy Report, June 1978, by
Envicom.
Riverside County Planning Department, January 1983, Riverside County Comprehensive
General Plan - County Seismic Hazards Map, Scale 1 Inch = 2 Miles.
Riverside County Planning Department, February 1983, Seismic-Geologic Maps, Murrieta-
Rancho California Area, Sheet 147, Scale 1" = 800'.
Southern California Earthquake Center (SCEC), 1999, Recommended Procedures for
Implementation of OMG Special Publication 117, Guidelines for Analyzing and Mitigating
Liquefaction Hazards in California, March 1999.
Temecula, City of, 1993, General Plan, adopted November 9, 1993.
Uniform Building Code (UBC), 1997 Edition, by International Conference of Building
Officials, 3 Volumes.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
EnGEN Corporation
VB
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
LABORATORY TEST RESULTS
Mr. Gerald staus
Projecl Number: T2944-GFS
Appendix Page 2
EnGEN Corporation
\,\
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
MOISTURE. DENSITY TEST REPORT
'l3
a.
~
'"
'"
r::
Q)
u
~
o
1\
\
\
,
\
\
1/ .....
) , l\
I 1\
/
I
I
I
I
~ "
\
\
\
- \
\
,
1\
128
126
124
122
120
118
4
ZA V for
Sp.G. =
2.53
16
6
8
10
Water content, %
12
14
Test specification: ASlM D 1557-00 Method A Modified
Elevl
Depth
Classification
UsCS AASHTO
Nat.
Moist.
%>
No.4
%<
No.200
sp.G.
LL
PI
SM
2.8
TEST RESULTS
Maximum dry density = 125.1 pef
Optimum moisture = 9.7 %
Project No. T2944-GFS Client: GERALD STADS
Project: STADS RESIDENCE
MATERIAL DESCRIPTION
SILTY SAND,BROWN
Remarks:
SAMPLE A
LOWER PAD AREA
COLLBY RW
COLL ON 8-22-03
. Location: DEL REY ROAD
MOISTURE - DENSITY TEST REPORT
ENVIRONMENTAL AND GEOTECHNICAL
ENGINEERING NETWORK CORPORATION
Plate
ZD
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
J(lb Number:
Job Name:
Location:
Sample S(lurce:
Sampled by:
Lab Technician:
Sample Descr:
use La~orat()ty Expansion Test Results
T2944-GFS
STAUS RESIDENCE
DEL REY ROAD
A (LOWER PAD AREA)
RW (8-22-03)
DJ
SIL TV SAND,BROWN
8/25/2003
Wet Compacted WI.: 612.4
Ring WI.: 194.9
Net Wet WI.: 417.5
Wet Density: 126.1
Wet Soil: 229.4
Dry Soil: 211.0
Initial Moisture (%): 8.7%
Initial Dry Density: 116.0
% Saturatiory: 52.0%
Final WI. & Ring WI.: 627.~
Net Final WI.: 432.9
Dry wt.: 384.0
Lo~: 48.9
Net Drywt.: 381.1
Final Density: 115.1
Saturated Moisture: 12.8%
Dial Change Time
Reading 1: 0.100 N/A 10:00
Reading 2: 0.101 0.001 10:15
Reading 3: 0.101 0.001 10:30
Reading 4: 0.101 0.001 25-Aug
Expansion Index:
1
Adjusted Index:
(ASTM D 4832-95)
1.8
EnGEN Corporation
41607 Enterprise Circle North
Temecula, CA 92590
(909) 296-2230
Fax: (909) 296-2237
Z\;
I I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
3000
RESULTS
0 C, psf 551
<P, deg 34.0
'>- TAN ~ 0.67
III
"- 2000
(f)
(f)
w
n::
f-
(f)
W
n:: 1000
::J
..J
~
SAMPLE TYPE:
DESCRIPTION: SILTY SAND,BROWN
SPECIFIC GRAVITY= 2.53
REMARKS: SAMPLE A
LOWER PAD AREA
COLL BY RW
COLL ON 8-22-03
Fig. No.:
CLIENT: GERALD STAUS
PROJECT: STAUS RESIDENCE
SAMPLE LOCATION: DEL REY ROAD,
MEADOWVIEW
PROJ. NO.: T2944-GFS DATE: 8-26-03
DIRECT SHEAR TEST REPORT
EnGEN Corporation
-z.z,
I
'.
I
I
I
I
.
I
I
I
I
I
I
I
I
I
I
I
I
Mr. Gerald staus
Project Number: T2944-GFS
Appendix Page 3
DRAWINGS
EnGEN Corporation
2-;;;