HomeMy WebLinkAboutEIA 97-05; SOUTH AGUA HEDIONDA INTERCEPTOR SEWER REACH 1E; SEWER MAIN SURCHARGE RECOMMENDATIONS; 1997-08-08SOUTHERN CALIFORNI
SOIL &TESTING, INC'.
c··
6280 Riverdale Street, San Diego, CA 92120
P.O. Box 600627. San Diego. CA 92160-0627
619-280-4321. FAX 619-280-4717
December 5, 1997
CanAm Properties, L.L.C.
5850 A venida Encinas, Suite A
Carlsbad, California 92008
ATTENTION: Michael Bryce
SCS&T 9611051.9
SUBJECT: Sewer Main Surcharge Recommendations, Sunny Creek Shopping
Center, El Camino Real and College Avenue, Carlsbad, California.
Gentlemen:
In accordance with your request, this report has been prepared to present our
recommendations for surcharging the area along the proposed sewer main that is
proposed along the east side of the subject property. We understand that this sewer will
be about buried about ten feet below the existing grade and will have a gradient of less
than 0.5 percent. The proposed grading in the area of the proposed sewer will result in
approximately ten feet of fill being placed above the existing grade_
The soils that underlie the route of the proposed sewer line are anticipated to be
comprised of about four to seven feet of loose to medium dense/medium stiff, recent
al1uvium, over a relatively competent older a11uvium. Our site preparation
recommendations are that the recent alluvial deposits be removed to the older alluvial
deposits and be replaced as compacted fill. This is based on the relatively low settlement
characteristics of the older alluvial deposits. However, this is also based on the
assumption that approximately one inch or less of settlement will occur due to the weight
of the fill to be placed to bring the site to finish grade elevation.
In consideration of the magnitude of settlement anticipated and the extremely flat
gradient of the proposed sewer line, it is our opinion that it will be necessary to surcharge
the route of the sewer line before the sewer line is constructed. The surcharge should be
placed up to at least the finish pad grade along the sewer line, and should be at least 20
feet wide at the top. The side slopes of the surcharge should be constructed at a slope
ratio of 2: I (horizontal to vertical). The unsuitable recent alluvial deposits should be
removed and be replaced as compacted fill prior to placing the surcharge. Settlement
monuments should be placed on the surcharge to determine when is will be safe to
construct the sewer line. The monuments should be monitored on a simi-monthly basis.
At this time, we estimate it will take somewhere between one and four months for the
surcharge to consolidate the older alluvial deposits.
If you have any questions after reviewing this report, please do not hesitate to contact this
office. This opportunity to be of professional service is sincerely appreciated.
Respectfully submitted,
SOUTHERN CALIFORNIA SOIL AND TESTING, INC.
Charles H. Christian, R.G.E. #00215
cc (3) Submitted
(3) Manitou Engineering