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j existing bench fill had theoretical factors of safety less than <br />• 1.0 for no fill removal and all phreatic conditions analyzed. <br />Factors of safety increased with increasing removal of the bench <br />fill, with the highest factors of safety occurring with complete <br />removal of the entire bench fill.,. The upper reclaimed slopes <br />were found to be stable for slopes which were equal to or less <br />than 30 degrees. These factors of safety were greater than or <br />equal to those determined for the existing natural slopes. As <br />1 with the condition of the operational slopes, the overall slope <br />stability of the highwall section, including the reclamation <br />slope, presented little potential for instability. <br />i <br />1 Based on the sensitivity analysis performed, the required factor <br />of safety (1.3) was achieved between 50 and 100 percent fill <br />removal. The final reclaimed slope was then established <br />utilizing this criteria with the exception that only the top <br />portion of the slope was removed and placed at the toe of .the <br />~ slope to establish a uniform, stable slope.The results of the <br />stability analysis performed on the final reclaimed slope are <br />presented in Table 4 and graphically shown on Figure 5. <br />JOINT STDDY - AIGAWALL AREA OPERATING MINE CONDITION <br />Detailed mapping of joints, bedding planes and other fractures <br />was performed in the sandstone and shale outcrops in the existing <br />highwall on site. All measured joint and fracture data has been <br />plotted on an equal area stereonet plot. These stereonets are <br />presented in Appendix A. One plot has been shown for the <br />1 sandstone members, another for the shale members, and yet a <br />~• third, presenting a composite of the sandstone and shale data. <br />7 <br />