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observed at an angle of repose on the order of 38 degrees. Therefore, <br />for purposes of this analysis, an effective stress friction angle of <br />38 degrees has been assigned to this layer. <br />The assumed position of the water table under the most severe <br />conditions is extremely important in a stability analysis. Considering <br />the steep topography of the area, and the proposed future grading which <br />would not be conducive to the impounding of water, we would assume that <br />the soil materials in this area would remain relatively dry. However, <br />under the best of drainage conditions, some infiltration of water into <br />the subsurface will occur. Therefore, it has been assumed that under <br />the worst conditions a perched water table will exist in the vicinity <br />of the toe of the existing bench fill, with seepage exiting from the <br />' toe area. We have also assumed that a true phreatic condition will not <br />develop in the foundation materials in the slope below this existing <br />fill. <br />Many different combinations of slope treatment have been considered <br />in this analysis which are too involved to describe in the body of this <br />report. However, a detailed graphical representation of all the slope <br />models considered in this analysis will be found in the Appendix of <br />this report in the map pocket. These include loading berm configura- <br />tions required to stabilize some of the alternatives considered. <br />1 SLOPE STABILITY ANALYSIS: <br />A slope stability analysis has been perS~rmed on the mathematical <br />models described in the previous section. There are many methods for <br />slope stability analysis which are in common use. Stability analysis <br />for this project was performed using a computer-assisted limit equili- <br />' brium method of. slices. This particular computer program utilizes <br />Spencer's method. <br />I -8- <br />