Laserfiche WebLink
4. Highwall Stability Analysis <br /> The highwall stability section of this TR addresses the slope stability analyses that were <br /> conducted to support the revised South Quarry highwall design. The purpose of the stability <br /> analyses is to evaluate high wall stability associated with increasing the interbench highwall <br /> heights (from 40H:4OVto 25H:70V) and to develop an optimum highwall configuration that <br /> is meets industry standards for assumed stability while optimizing South Quarry reserves. <br /> 4.1 Kinematic Analyses <br /> Data obtained during GEI's South Quarry mapping to support the 2013 through 2016 <br /> Geotechnical Addendum to the Annual Report for M-1973-021, discussed in Section 2.3 <br /> above, was utilized in the development of the kinematic analysis. Two and three- <br /> dimensional modeling utilizing the mine highwall analysis software suite developed by <br /> Rocscience was conducted to evaluate various modes of kinematic highwall failures. The <br /> various modes and software used are described below: <br /> • Dips (V7.0)—graphically analyze and visualize structural data obtained within the <br /> South Quarry utilizing stereonets in two-dimensions. <br /> • Planar Failure (RocPlane V3.0)—interactive analysis tool for evaluating the <br /> possibility of planar sliding failure in rock slopes in two-dimensions. <br /> • Wedge Failure (SWedge V6.0)—interactive analysis tool for evaluating the stability <br /> of surface wedges in rock slopes, defined by two intersecting discontinuity planes,the <br /> slope surface and an optional tension crack in three-dimensions. <br /> • Toppling Failure (RocTopple V 1.0)—interactive analysis tool for evaluating block <br /> toppling in rock slopes in two- and three-dimensions. <br /> For the kinematic analyses,three primary highwall orientations were assumed within the <br /> South Quarry(Figure 3): <br /> • East highwall (north/south) Trending 180'—dipping 45' to the east(90' dip <br /> direction) <br /> • West highwall (north/south) Trending 0°—dipping 67'to the west(270' dip <br /> direction) <br /> • South highwall (east/west) Trending 90'—dipping 67' to the north(0' dip direction) <br /> Aggregate Industries Morrison Quarry GEI Consultants, Inc. <br /> South Quarry Highwall Design Technical Revision 13 August 2017 <br />