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Table 7-5. Slope Stability Analyses Results: West Quarry Global and Local Stability <br /> Factor of Safety (FOS) <br /> Highwall Analysis Case <br /> SLOPE/W FLAC/Slope <br /> Global 2.01 1.57 <br /> Global w/ Sillimanitic Gneiss 1.52 1.29 <br /> West Highwall Local: 30 ft Bench at El. 7,000 1.30 <br /> (East Facing) Local: 40 ft Bench at El. 7,000 1.32 1.28 <br /> Local: 30 ft Bench at El. 6,650 <br /> Local: 60 ft Bench at El. 6,650 1.27 1.33 <br /> Global 4.30 4.44 <br /> East Highwall <br /> Global w/ Sillimanitic Gneiss 3.45 3.53 <br /> (West Facing) <br /> Local 1.70 2.40 <br /> Note: <br /> 1.) All future benches above El.7,000 ft have been modeled with a highwall height of 40 ft,width of <br /> 65 ft, and a face angle of 90°as this cell will be flatter than benches and highwalls below El. 7,000. <br /> The computed FOS above El. 7,000(up to El.7,320)is 1.57 that exceeds the State required FOS of <br /> 1.25 for global stability. <br /> The results show in Table 7-5 indicate adequate global stability, with FOS' ranging from <br /> 1.52 to 4.30 and 1.29 to 4.44 for SLOPE/W and FLAC/Slope, respectively (including <br /> variation with the highwall and the presence of Sillimanitic Gneiss). The analyses indicate <br /> the configuration does not meet minimum criteria if a 30-ft wide bench is included at El. <br /> 7,000 feet or El. 6,650 feet. A 40-foot minimum width for the top bench at El. 7,000 and a <br /> 60-foot minimum width for the intermediate bench at El. 6,650 feet is required to meet <br /> minimum State standard of FOS of 1.25 for the West Quarry West Highwall (East Facing). <br /> 39 <br /> Aggregate Industries—Morrison Quarry GEI Consultants, Inc. <br /> AM-07 Geotechnical Stability Exhibit November 2020 <br />