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1 In order to provide the maximum information on the nature of <br />I on site stability conditions, a sensitivity analysis was <br />performed. This type of analysis identifies the most important <br />factors with respect to construction of the stability model and <br />their effect on stability. Four separate conditions were <br />investigated as follows: <br />1. The first model assumed residual strength behavior in <br />the colluvial (landslide debris) materials. In addition. the <br />most typical shear strength condition anticipated for the <br />_I interbedded sandstone, siltstone and shale bedrock was utilized <br />in the analysis. A 4-foot thick seepage zone at the <br />1 bedrock/colluvium interface was utilized in the determination of <br />internal pore pressures in the colluvial soil mass. <br />2. The second condition considered involved all of the <br />assumptions used in condition #1 (residual strength in colluvium <br />1 and typical shear strength parameters for bedrock), but <br />7 eliminated all seepage. In other words, internal pore pressures <br />1 were assumed to be zero throughout. <br />1 3. The third condition replaced the residual strength <br />parameters with the peak strength parameters in the colluvial <br />1 soil. Once again, however, the typical shear strength parameters <br />for bedrock were utilized and the 4-foot thick seepage zone at <br />the bedrock/colluvium interface was replaced. <br />1 4. The fourth condition considered once again utilized peak <br />strength values for the colluvial soil, but utilized the lowest <br />1 possible shear strength values for the bedrock materials (i.e. <br />shearing along a surface parallel to the bedding planes in a <br />8 <br />