HomeMy WebLinkAboutTract Map 3883 Lot 165 Soils
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. Geology. Water Resource Slui:Iies . Phase I & II Environmental Site Assessments
ENVIRONMENTAL & GEOTECHNICAL ENGINEERING NETWORK
October 26, 1998
Mr. Kenneth Murphy
520 Roosevelt
Corona, CA 91719
Regarding:
Soils Report, Single Family Residence
APN 919-140-008
Paseo Sereno, Meadowview Area
City of Temecula, California
Project Number: T1447-LGS
Reference:
California Group A & E, Grading & Drainage Plan/Site Plan,
plans dated May 22, 1998.
Dear Mr. Murphy:
EnGEN Corporation has been retained by Mr. Kenneth Murphy to perform the
Geotechnical Engineering for the proposed grading on the referenced lot. It is
our opinion that a Preliminary Soils Investigation is not necessary for the work
proposed on this site.
The history of the Meadowview area is one of well known, fairly consistent
geotechnical characteristics, to the degree that an investigation would not be
expected to provide any new data, nor any different recommendations for the
proposed grading procedures or the design of the structure's foundation system,
from the recommendations made in this letter.
The earth materials underlying the area are known to consist of stable units of
Pauba Formation, sandstones and siltstones, along with alluvial materials in the
canyons. The regional geology has been thoroughly mapped by Michael
Kennedy, and presented in his "Special Report 131, Recency and Character
of Faulting Along thfl~inore Fault Zone in Southern Riverside County,
___".._.,,,,v~
:'~"""S:~alifornia", 1977,CaliJ'amiaDivision of Mines and Geology. As clearly
" ')(':IiJcumented.py.t'~~nnedy,itheentire,.area is underlain by units of the Pauba
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Mr. Kenneth Murphy
Project No: T144 7 -LGS
October 1998
Page 2
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These earth materials have historically been considered stable, as evidenced by
the absence of geotechnical instability problems in the area. Prior to the
formation of the City of Temecula, the County of Riverside, then the controlling
agency, recognized the documented stability of the area and did not require
preliminary soil investigations for single home development in this area.
Similarly, upon recommendations of the Geotechnical Engineer, the City of
Temecula has permitted design and grading operations without the expense of a
preliminary soils investigation.
Based on the relatively simple grading proposed for the site, no unusual
conditions are anticipated which cannot be mitigated during grading. The
following grading recommendations are presented based on our familiarity with
the area and the earth materials expected to be encountered:
1. Removals in areas underlying the proposed structure and in areas to receive
fill should extend to Pauba Formation bedrock or competent alluvial
materials. Removal depths should be determined by a staff geologist from
EnGEN Corporation during grading operations. Overexcavations (if
necessary) of proposed cut areas on the proposed pad underlying the
proposed structure area should be performed so that a minimum of 2 feet of
compacted fill exits below the bottom of the structure footing. Overexcavation
should extend a minimum of 5-feet outside the perimeter footings. An
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alternative would be to extend all footings into Pauba Formation bedrock.
2. Benches shall be cut into firm natural ground such that all fill is placed on
level ground.
3. All exposed natural ground shall be scarified to a minimum depth of 6 inches,
moisture conditioned as necessary, and recompacted prior to placement of
fill.
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EnGEN Corporation
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Mr. Kenneth Murphy
Project No: Tl447-LGS
October 1998
Page 3
4. All fill shall be brought to within 2% of optimum moisture content and shall be
compacted to at least 90 percent of maximum density.
5. Both cut and fill slopes should be constructed at angles no steeper than 2
(horizontal): 1 (vertical). Fill slopes on natural slopes with gradients steeper
than 5: 1 (horizontal to vertical) should have a keyway constructed at the toe
of the slope.
6. Any proposed cut slopes should be observed during grading operations by a
staff geologist from EnGEN Corporation to verify the stability of the cut slope.
7. Our representatives will be on the site to perform density testing and
inspection to assure that the above recommendations are adhered to and to
verify that the grading is being performed in an acceptable manner. A report
of Rough Grading will be prepared upon completion of the grading. If any
design or construction recommendations are in order they will be made in the
report and will be presented together with the results of density testing.
The opportunity to address this matter, and your consideration of this request is
greatly appreciated. If you have any questions regarding these issues, please
do not hesitate to call.
Respectfully submitted,
~'PO"'iO"
OSbj~at~ne E 162
Princi I Geo echnical Engineer
Expires 9/30/01
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Distribution: (4) Addressee
File: EnGENIReportingIGsIT1447LGS Kenneth Murphy
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EnGEN Corporation