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<br />• piles have been constructed. <br />The factor of safety for deep-seated failures, whe^e the shear <br />surface passes through the underlying colluvium, is calculated to be <br />1.32 under dr,y conditions; under wet conditions, the safety factor is <br />reduced to 0.88. <br />The safety factors for this waste pile configuration are con- <br />sidered to be unacceptable even for temporary waste piles. this is par- <br />ticularly the case since piles constructed on steep slopes frequentl,v <br />tie directly above Ralston Creek. As it is practically impossible to <br />stabilize the pile of this configuration, the removal of the waste pile <br />material from slopes of this grade (or steeper) is a necessity. Deposition <br />of waste pile material on slopes of a similar character should be <br />avoided in the future. <br />• 4.4 Future Configurations <br />In this section, consideration is given to the future develop- <br />ment of the waste piles between the present time and the atandonment of <br />the mine. In the context of slope stability, the results of the analyses <br />that assumed existing configurations can be taken into account. The <br />analyses of the existing configurations have shown that no serious <br />stability problems do exist on the site except for waste File portions <br />that have been placed on steep natural slopes. It has been shown earlier <br />that both east and west piles can be expanded north and south to obtain <br />additional storage volumes. It has also been shown and assumed that in <br />addition to expanding the waste piles laterally, the heights of the exist- <br />ing piles can be increased. Such expansions have been discussed in detail <br />in Section 4.1, Waste Pile Expansions. <br />The proposed expansions have been used as a basis to calculate the <br />stability of the waste piles with increased height. <br />• <br />- ~4 - <br />