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strength properties of the reclaimed materials, unconfined compressive strength samples were prepared using materials from each curve sample. Sample 2, which contained more aggregate, was compacted in a 4-inch diameter mold to a dry density of 119.9 pcf or approximately 90 percent compaction. Sample 1, which was composed of more fine-grained materials, was V2 compacted in a 2 /2 inch diameter brass sleeve at an initial density of 94.7 pef or 82 percent j compaction. The unconfined compressive strengths for these two samples were 21 and 12 psi, respectively. Although undrained strength parameters based on these test results would exceed 850 pounds per square foot (psf), we have conservatively used a cohesion value of 150 psf (drained strength) and an angle of internal friction of 28°. Both values are much lower than used for other reclaimed slope studies in San Joaquin County. The slope stability analysis was performed using the program SLOPE W, which has been used for previous stability analysis for Granite, Teichert, DSS, and Brown pit studies in Sarij Joaquin County. The slope configuration, as well as the input parameters, are presented on the 4attached plate. As with previous studies on reclaimed slopes, the input values for the reclaimed slopes are lower than the adjacent partially-cemented clay and sandy gravel materials. Numerous undisturbed block samples have been obtained from various gravel pits in this area, although mostly on the west side, and cohesion values for the native undisturbed sand and gravel materials have been at least 900 psf. In our analysis we have conservatively used 500 psf As noted by the attached plate, the computed factor of safety under static loading was 1.63, above the 'required - value in Section 9-1415.3(k)(7). In summary, it is our opinion that a proposed change to the Conditions of Approval is warranted. As noted above, a relatively high factor of safety is available for the proposed 2:1 reclaimed slope. In addition, there are numerous reclaimed slopes at the other aggregate facilities in San Joaquin County (Granite, Teichert, DSS, Brown Sand and Lonestar) which have similar or steeper reclaimed slopes and which are performing satisfactorily. We trust this letter summarizes the information requested. If you have any questions°or need additional information,please contact us. Respectfully submitted, V oFESSlajy KLEI LDER, NC. �o t 1y ae CZ o „+ C No. 388 a Exp. 3-31-03 Ron Heinzen, G.E. Regional Manager/ Senior Principal `f ox CA1�FQ�� RH:md 20-2245-1 1.G02/201 l L800 November 20,2001 Copyright 2001,Kleinfelder,Inc. Page 2 of 2 KLEINFELD£R 2825 East Myrtle Street,Stockton, CA 95205-4794 (209)948-1345 (209)948-0621 fax