HomeMy WebLinkAboutCDP 98-40; Severino Residence; Coastal Development Permit (CDP) (9)¥SOUTHERN CALIFORNIA
SOIL & TESTING, INC.
6280 Riverdale Street, San Diego, CA 92120
PO. Box 600627, San Diego, CA 92160-0627
619-280-4321, FAX 619-280-4717
September 8, 1999
Severino Construction SCS&T 9811024.5
2186 Batista Avenue
Vista, California 92084
SUBJECT: Update Report, Parcel 3, Map Number 16177, Park Drive, Carlsbad California.
REFERENCES: 1) "Summary of Field Observations and Tests for Relative Compaction, Parcel
3, Map Number 16177, Park Drive, Carlsbad California," by Southern
California Soil and Testing, Inc., dated January 28, 1999.
2) "Report of Geotechnical Investigation, Parcel 3, Map No. 16177, Park
Drive, Carlsbad, California," by Southern California Soil and Testing, Inc.,
dated April 29, 1998.
Gentlemen:
In accordance with your request, this report has been prepared to provide an update for the subject
site. The subject lot is currently occupied by a single-family residence which is under construction.
Issues have arisen regarding undocumented fill soils which are present hi the slope which ascends
from the retaining wall located at the northeastern property line of the subject lot, and which extend
onto the adjacent lot to the northeast (Parcel 2). The issues concern the effect mat the undocumented
fill soils might have upon the subject lot, particularly in regard to a proposed access driveway to be
constructed along the southeastern property line of the two lots, and a drainage device to be
constructed at the northwestern property line. It is our understanding that permission has been
obtained from the owner of Parcel 2 to perform any necessary remedial grading.
Four backhoe trenches were excavated at the locations shown on Plate Number 1 on July 19, 1999.
In Trench Number 1, four feet of undocumented fill was encountered, underlain by 3.5 feet of
topsoil deposits. In Trench Number 2, three feet of undocumented fill was encountered, underlain
by two feet of topsoil. The fill and topsoil deposits in both trenches were underlain by medium dense
to dense terrace deposits. In Trenches 3 and 4, medium dense to dense terrace deposits were
encountered at pad grade. The approximate estimated limits of the undocumented fill is depicted on
Plate Number 1.
SCS&T 9811024.5 September 8, 1999 Page 2
The undocumented fill and topsoil deposits are not considered suitable, in their present condition,
for the support of settlement-sensitive improvements. In addition, the undocumented fill and topsoil
deposits exposed in the fill slope may be prone to erosion and/or slumping. It is therefore
recommended that all undocumented fill and topsoil deposits be removed and replaced as compacted
fill. The estimated maximum combined depth of the undocumented fill and topsoil deposits is about
nine feet near the location of Trench Number 1. In order to reduce the risk of differential settlement
for any future residential structure which might be constructed on Parcel 2, the cut area of Parcel
2 should be undercut to a minimum depth of three feet below pad grade. The undercut surface
should be sloped toward the fill end of the lot at a minimum gradient of two percent to reduce the
potential for ponding of groundwater on the terrace deposit/fill contact.
Southern California Soil and Testing, Inc., did not observe the placement of the backfill. Based upon
our conversation with Mr. Ron Severino, the existing property line retaining wall was backfilled
with crushed rock wrapped in filter cloth. This should be verified during the removal of the
undocumented fill.
If you should have any questions regarding this report, please do not hesitate to contact this office.
This opportunity to be of professional service is sincerely appreciated.
Respectfully submitted,
SOUTHERN CALIFORNI ING, INC.
Mike Farr, C.E.G. #1
DBA:MF:mw
cc: (6) Submitted
Daniel B. Adler, R.C.E. #:
N68'55'15'E 194.3$
SCS&T EXPLANATION
•• APPROXIMATE TRENCH LOCATION
Qaf COMPACTED FILL (TESTED BY SCS&T, 1998)
Quf UNDOCUMENTED FILL
Qt TERRACE DEPOSITS
^>SOUTHERN CALIFORNIA
SOIL & TESTING, INC.
PARCEL 3
BY: MF/KMS
JOB NO: 9811024.4
DATE: 9/9/99
PLATE NO: 1