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'• Stability conditions at the Blue Ribbon mine site were analyzed <br />utilizing a computer-assisted limit equilibrium method of slices. <br />I <br />This particular program utilizes Spencer's method of analysis. <br />j The program is capable of analyzing stability conditions under <br />circular and randomly specified shear surfaces. <br />Two conditions of slope failure were analyzed. These consisted <br />of: <br />o Evaluation of existing conditions for highwall, bench <br />fill and overall slope stability. <br />o Evaluation of stability under reclamation conditions. <br />Two sections were analyzed for stability, one through boring P2-2 <br />(Section B-B) and the other 70 feet south of boring P2-1 (Section <br />A-A). The approximate plan location for these sections are shown <br />~• on Figure 2 and the cross-sections are shown on Figure 3. <br />OPERATIONAL CONDITIONS <br />The stability of the existing operational slope was evaluated to <br />determine minimum factors of safety for the bench fill area, <br />highwall and the overall slope. Both circular and wedge type <br />failures were analyzed. <br />In order to provide the maximum information about the nature of <br />the site stability conditions, a sensitivity analysis was <br />f performed varying the phreatic conditions within the slope. <br />I The three separate phreatic conditions investigated were: <br />1 o Dry conditions - no phreatic surface. <br />1 o Phreatic surface four feet above rock surface. <br />~• o Phreatic surface at various depths within the bench fill. <br />5 <br />