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AR15 <br />Stability Analyses: Please have HDR provide rational for defining a <br />circular failure plane for each scenario in the slope stability analyses <br />when it was determined that wedge failure is the most probable failure <br />mode at the Mine as a result from the kinematic analysis. <br />In general, while there is high probability of wedge and other kinematic failure <br />mechanisms within the quarry, the frequency of fractures and jointing lends itself <br />to smaller scale raveling and stress relief. Kinematic failure would likely be on the <br />order of a few cubic feet. It is unlikely that any kinematic condition develops on a <br />larger scale because the rock mass is so heavily fractured. <br />It is of far more reasonable concern that a weathered section (particularly in the <br />talc-gneiss regions) experiences a mass flow event which would generally exhibit <br />a circular or non-circular pattern. SLIDE2 analyses were utilized to check the <br />circular case, and FLAC/Slope was utilized to check the non-circular case. The <br />FLAC analyses are located within Appendix C and are discussed in Section 5. <br />AR16 <br />Per Section 30 of the Policies of the Mined Land Reclamation Board, for <br />strength measurements resulting from multiple tests for non-critical <br />structures, the minimum recommended FOS is 1.25 for static <br />conditions and 1.1 for seismic conditions. No seismic conditions were <br />provided or evaluated by HDR in the Report. In order to ensure all <br />requirements of Section 30 are satisfied, please have HDR provide <br />stability analyses for the Mine under seismic conditions for all <br />scenarios along with rational for the associated seismic load applied. <br />Added seismic evaluations in Appendix C and discussion related to seismic <br />evaluation in text Section 5.2.3.2 - Seismic Analyses. <br />Appendix A, Section 5.2.3.2, p. 27, <br />document Appendix C. <br />1