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intersection of the planes for discontinuity sets P-2 and P-4 lies just outside the <br />33° friction angle, which would be an indication of conditions conducive to sliding <br />along the intersection. <br />The wedge stability analysis for the southeast wall indicates one plunge of the <br />line of intersection that daylights in the slope face. The intersection of the planes <br />for discontinuity sets P-3 and P-6 each lies just within the 33° friction angle, <br />again indicating that conditions may be conducive to sliding along the <br />intersection. This condition has been noted in past reports, and the south walls <br />should be continued to be monitored as excavations continue. <br />As mentioned previously for the east wall, the individual benches along the south <br />walls with near vertical faces enable additional discontinuities to form potential <br />wedges that may slide during the temporary condition prior to reclamation. <br />Wedge failures limited to individual benches have been consistently observed in <br />the past a-ong the south walls. <br />In previous annual reports, toppling about discontinuity plane P-1 also existed as <br />another mechanism of potential block movement for the southeastern wall. <br />However, as shown on Figure 16 both the slope face and discontinuity plane P-1 <br />no longer share the same basic strike. A review of photographs during previous <br />annual reviews does indicate that there are some large continuous sun`aces that <br />form the face of the south wall. However, none of these surfaces appear to be <br />discontinuity plane P-1, which has a dip of 72° to the south. <br />The foliation also strikes in the same general orientation as both the slope face <br />and discontinuity plane P-1, although at an overall shallower dip. It is believed <br />that the foliation will prevent large failure surfaces from developing along the <br />south wall simply by creating a systematic set of blocks that can dislodge. This <br />has been observed in the rock exposures on the south wall that have a broken <br />reverse-stepped orientation, and that also expose the undersides of the foliation <br />surfaces. <br />-18- <br />