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possible combinations of joint intersections which can form a wedge, and develop a <br /> minimum factor of safety for each wedge. <br /> In all cases, the assumed failure mode of the wedge is translational slip—rotational slip and <br /> toppling are not considered. The analysis type used for this analysis was deterministic, as all <br /> the input parameter are known. <br /> Swedge required slope input data included the plane orientations, slope height, and rock unit <br /> weight. The strength model used to determine the shear strength of the joints was Mohr- <br /> Coulomb. The orientation and waviness of the two intersecting joints is required to run the <br /> Swedge model. No external pressures (water pressure and seismic) were applied for these <br /> cases. <br /> 4.1.3 Toppling Failure <br /> Toppling failure occurs when the discontinuities within the mine highway are near to parallel <br /> with the slope of the face, creating a parallel series of slabs that can topple into the pit. Using <br /> highwall orientation(trend)and mapped discontinuity characteristics, RocTopple can <br /> compute all discontinuities which can form a parallel series of slabs, and develop a minimum <br /> factor of safety for each series of slabs. The RocTopple model analyses when slabs will slide <br /> as a mass and which slabs will topple. The model can also identify if any of the slabs will be <br /> in tension during a toppling failure. <br /> The main input for RocTopple is the geometry of the slope and structural discontinuities, and <br /> the strength of the joints. The Mohr-Coulomb strength model was used for this case. <br /> 4.2 Global Stability Analysis <br /> SLOPE/W and FLAC/Slope were used to analyze the highwall assuming the typical (Hoek <br /> Brown criteria)and laboratory developed properties(ie direct shear results) applied to the <br /> entire rockmass, although observations and samples were obtained from discrete locations <br /> within the quarry. Both programs were utilized to provide a confirmation"check"on the <br /> results of each program. Stability analyses were performed using both programs for two <br /> cases: <br /> • The entire South Quarry highwall modeled with estimated GSI classification strength <br /> properties and were purposely very conservative. These classification properties <br /> were obtained using the RocScience RocLab (V 1.0)program by developing a <br /> Geological Strength Index(GSI)based on GEI observations and experience with the <br /> Gneissic rock types within the South Quarry. The selected Hoek Brown parameters <br /> with the associated Mohr-Coulomb strength criteria are presented below. Intact <br /> compressive strength was based on laboratory derived compressive strength values <br /> developed during previous field investigations. The disturbance factor of 1 was used <br /> due to the material being excavated by blasting. The material parameter mi was <br /> Aggregate Industries Morrison Quarry GEI Consultants,Inc. <br /> South Quarry Highwall Design Technical Revision 15 August 2017 <br />