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Runs #7 through #11 use one soil with varying cohesions and pore <br />pressure ratios but keeping the friction angles relatively <br />constant. None of these runs meet the required safety factor. Run <br />#7 uses parameters which are expected in the field for the case of <br />stiff ground over the entire road surface. Run #12 uses the <br />expected field parameters for the case of two soils. It also does <br />not meet the required safety factor of 1.3. The failure arcs for <br />Runs #7 and #12 are shown on Exhibit 3. <br />Run #11, using higher than expected strength values and a <br />reasonable pore pressure ratio, is included as an example in <br />Appendix B of this report. <br />Overall, no realistic combination of soil parameters and slope <br />geometry yields an acceptable safety factor. Runs using no pore <br />pressure ratio and high cohesion do result in high safety factors <br />but the lab tests show that the material is not very cohesive. <br />Also, it must be assumed that water will infiltrate into the fill <br />in the future, especially considering the heavy snowfall and lack <br />of appreciable fines in the material. <br />13 <br />