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HomeMy WebLinkAboutCT 73-18; Carrillo Estates; Soils Report; 1975-06-24,!y ;<a-’ ’ ) i “-.TL - WOODWARD-CLYDE CONSULTANTS CONSIJLTING ENGINEERS. GEOLOGISTS AND ENVIRONMENTAL SCIENTISTS WESTERN REGION 3467 Kurtz Street San Diego California92,10 June'24, *_-- IYl3 Project No. 73-203 Phone (714) 224-2911 Ponderosa Homes, Inc. 2082 Business Cent-r Drive, Suite 100 Irvine, California 92664 Attention: Mr. Terry Teeple / I 6’ 13 ADDITIOIJAL SLOPE STABILITY ANALYSES CARILLO ESTATES CARLSBAD, CALIFORNIA In accordance with the request of Mr..Norm Arndt of Rick Engineering Company, we have reviewed the grading plans for the proposed Carillo Estates to be located approximately 1 mile east of'E1 Camino Real, and 1 mile south of Palomar .Airport Road in Carlsbad, California. The purpose of our review is to determine if the grading plans were prepared in accordance with the conclusions and recpmmendations in the preliminary soil report entitled "Soil Investigation for the Proposed Carillo Estates, Carlsbad, California", dated September 7, 1973, prepared by Uoodward- Gizienski &'Associates. The undated and untitled grading plans provided us were prepared by Rick Engineering Company. They indicate that 2:l inclined slopes, having maximum heights Df 66 and 120 feet for cut and fill slopes, respectively, are proposed. Six foot benches are provided in fill slopes on 30 foot intervals which results in somewhat flatteroverall slope inclination of the major slopes. It was also noted that most of the higher slopes will be formed by filling canyon areas at the northeast and southwest portions of the site, hence confining the fill.mass. There are also l-1/2:1 inclined cut and fill slopes having respective maximum heights on the order of 25 and 20 feet. As a part of the preliminary soil investigation, analyses were presented for cut and fill slope with heights and inclinations of bless than 50 feet and l-1/2:1, respectively. Analyses of fill slopes inclined on 2:l indicated allowable heights on the order of 115 feet. No analysis was made for 2:l inclined cut slopes. !3010.21.59 .I Ponderosa Homes, Inc. Page 2 Project No. 73-203 .I t -~ June 24, 1975 Two slope conditions are not covered by the preliminary report: The 2:1 fill slope exceeding the allowable 115 feet height by 5 feet, and the 2:1, 66 foot high cut slope. In the case of the higher fill slopes, a review of our slope stability calculations indicates that the added 5 feet in height does not significantly effect the indicated factor of safety against deep-seated slide failure. The recommendation for use of special materials in the lower portions of these high fill slopes should be observed. In the case of the 66 foot high 2:l cut slope along the prDpDSed access road, a review of our data concerning the geologic conditions in this area indicates that it will be underlain by Santiago Peak volcanics in the lower portion of the slope, and dense sands of the Delmar formation in the upper portion of the slope. It is our opinion, provided the condition of the rock is sound, that the slope will have an adequate indicated factor of safety against deep-seated slide failure. It is recommended, however, that the slope be inspected during and at the close of grading by an engineering geologist from our office to determine the actual geologic conditions. If adverse soil or rock conditions are encountered, such as badly fractured rock, clay seams or water seeps, buttressing of the slope may be required. .If you have any questions concerning our additional slope stability analyses, please call or write the engineer assigned to this project, Mr. Richard P. While of our firm. WOODWARD-CLYDE CONSULTANTS LJL/RPW/jr (2) Ponderosa Homes, Inc. (1) Rick Engineering Company Attention: Mr. Norm Arndt WOODWABD-CLYDE CONSULTANTS