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rock. The colluvial material terminates at the top of the slope <br />• where excavations had been made for the main bench and <br />installation of the mine facilities. The vertical thickness of <br />the colluvium utilized in the stability model was on the order of <br />eight feet. The bench fill material varied between 0 and 25 feet <br />in thickness. Details of the cross-sections utilized for the <br />stability analysis are presented in Figures 3 and 5. <br />Although no free water was observed in the fill or colluvial <br />materials on site at the time of drilling, various thicknesses of <br />seepage zones at the colluvium bedrock interface and within the <br />fill material were assumed, for the purpose of the stability <br />model. <br />The' following specific values for Shear strengths were utilized <br />• in the various phases of the analysis. <br />o Bench fill (existing): <br />c = 374 psf <br />D= 160 <br />o Bench fill (recompacted): <br />c = 446 psf <br />S= 190 <br />o colluvial soil: <br />c = 446 psf <br />~= 19° <br />o Interbedded sandstone and shale: <br />c = 4000 psf <br />H= 330 <br />i• <br />4 <br />