HomeMy WebLinkAboutCT 05-13; LA COSTA RIDGE NBHGD 2.6; LETTER ADDRESSING EMBANKMENT CONSTRAINTS; 2007-02-21'a' PACIFIC SOILS ENGINEERING, INC. -7715 CONVOY COURT, SAN DIEGO, CALIFORNIA 92111
TELEPHONE: (858) 560-1713, FAX: (858) 560-0380
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D.R. HORTON INC.
5790 Fleet Street, Suite 210
Carlsbad, CA 92008
Attention:
SubjeCt:
References:
Gentlemen:
Mr. Kevin Kasai,
Forward Planner
Embankment Constraints, La Costa Ridge
Neighborhood 2.6, Carlsbad, California,
February 21,2007
Work Order 401036
See Appendix CTo5-L3
Pursuant to your request, Pacific Soils Engineering, mc. (PSE) has prepared this letter addressing
,embankment constraints for the La Costa Ridge Neighborhood 2.6, Carlsbad,.Califomia. Along
the eastern property line are various sewer and reclaimed water lines. These lines consist of a
variety of materials, including transite, vitrified clay and ductile iron pipe. The current grading
plans depict grading and the construction of supeljacent slopes andlor retaining walls within four
(4) to five (5) feet of these lines.
To evaluate what effect the proposed development could have on these improvements, PSE has
prepared cross-sections A-A' through F-F' (Plate 2) depicting the geologic contacts, existing and
proposed grades and these existing buried lines. The approximate locations of these cross.,
sections are presented on the grading and erosion plans, prepared by David Evans and Associ-
ates, mc. (plate 1). m preparing these cross-sections, PSE used'the as-built plans of the ten-(10)
inch force main and the eight-(8) inch sewer main to determine the approximate elevation of
these lines. PSE did not have as-built plans for the reclaimed water line. However, we have as-
surned a "worst-case" elevation for this line of approximately nine (9) feet below grade .
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TEL: (714)220-0770
FAX: (714) 220-9589
LOS ANGELES COUNTY
TEL: (310) 325-7272 or (323) 775-6771
FAX: (71"4) 220-9589
RIVERSIDE COUNTY
TEL: (951) 582-0170
FAX: (951) 582-0176
SOUTH ORANGE COUNTY
TEL: (714) 730-2122
FAX; (714) 730-5191
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Work Order 401036
February 21,2007
Page 2
As depicted on Plate 1 and 2, PSE has detennined the limits of structural influence that could
conceivably affect these buried lines. This influence line is a 1 : 1 (horizontal to vertical) projec-
tion from the bottom of the lines upward to existing grade. The location of this structural influ-
ence line is presented in Sections A-A' through F-F' (Plate 1) and on Plate 2.
Accordingly, it is PSE's recommendation that the proposed design should be modified such that
loading from superjacent fill slopes or retaining walls is outside of this 1 : 1 projection.
Should you have any questions regarding this letter, please contact the undersigne~l.
Dist: (3)
(2)
(2)
c.
Addressee
D.R. Horton, Attn: Mr. John Owen
David Evans and Associates; Attn: Mr. Gabriel Rodriguez
JAC/JAH:bm:40I036, February 21, 2007
PACIFIC SOILS ENGINEERING, INC.
Work Order 401036
February 21,2007
REFERENCES
AP PEN,DIX
Pacific Soils Engineering, Inc., 2007a, Updated Preliminary Geotechnical Investigation, La
Costa Ridge Proj ect, in the City of Car1s~ad, California, by Pacific Soils Engineering,
me., dated February 15, 2097 (Work Order 401036).
Pacific Soils Engineering, me., 2007b, Preliminary Geotechnical Investigation, La Costa Ridge
Project (Approximately 7+-Acre Parcel), in the City of Carlsbad, California, by Pacific Soils
Engineering, Inc., dated June 2,2005 (Work Order 401036).
Pacific Soils Engineering, Inc., 2006, Suitability of Stockpile Material, La Costa Ridge 2.6-Acre
Parcel, Located Southwest of Rancho Santa Fe Road and Melrose Drive, City of Car1sb~d,
CA, dated February 15, 2006 (Work Order 401036).
Pacific Soils Engineering, Inc., 2005a, Preliminary Geotechnical Investigation, La Costa Ridge
Project (Approximately 7+-Acre Parcel), in the City of Carlsbad, California, dated June 2,
2005 (Work Order 401036).
Pacific Soils Engineering, Inc., 2005b, Geotechnical Summary, La Costa Ridge 2.6-Acre Parcel,
Located Southwest of Rancho Santa Fe Road and Melrose Drive, City of Carlsbad, CA,
dated March 29,2005 (Work Order 401036).
PACIFIC SOILS ENGINEERING. INC.
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San Marcos Creek-Developed
San Marcos Creek 1
plan: Dev-Normal-Depth 3/5/2007
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Main Channel Distance (ft)
1 in Horiz. = 100 ft 1 in Vert. = 5 ft
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Crit PF#1
Ground
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