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JunuarY 15. 2008 <br />!'qge 46 <br />41 <br />ilk <br />Air, <br />AK, <br /> <br />Figure 32. Photograph of Surface Cracking Associated with 2001 Highwall Failure in <br />GTest Pit Downdip of Z Dip Pit Barrier Pillar Area <br />results indicate that the L-Dip hillside is expected to remain stable under the assumed conditions. <br />Figure 33 shows that only minor near-surface failure is expected as predicted by inelastic failure <br />indicators and low equilibrium velocities. Almost all of the localized failure shown in this figure <br />was induced by previous G-Test Pit mining. The low velocities indicate the model comes to an <br />equilibrium state and the slope is stable. The assumed high groundwater and low I.-Roof <br />mudstone strength are conservative. Recent laboratory testing of 7.-Dip Pit rock samples <br />(Table I ) show significantly higher L-Roof mudstone strengths compared to post-landslide <br />samples from G-pit. Long-term groundwater records indicate significantly lower groundwater <br />elevations than assumed to induce instability of G-Pit, even during peak precipitation periods. <br />The analysis indicated the slope has an estimate safety factor of over 4.0. <br />Conclusions for the /-Dip Pit stability analysis results are summarized as follows. <br />The hillside is expected to remain stable during!.-Dip mining. even under severe <br />groundwater and low strength conditions. <br />• The analyses are conservative because the extreme conditions assumed in the model have <br />not been observed. <br />Agapito Associates, Inc.