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well as desire to align the highwall as parallel as possible to the west boundary of <br />property (basically N -S), over the past 15 years the alignment of the benches has <br />migrated to approximately N10W. Where foliation is aligned with the primary joint <br />direction, the highwall bench faces appear clean and almost monolithic. In areas where <br />foliation strike intersects the primary joint strike and bench alignment direction at high <br />angles, bench edges break at high angle to a final disturbed face alignment, creating a <br />rougher overall appearance. While this condition does not appear to weaken the overall <br />bench stability, it does result in localized rock fall from the edge of the mine bench onto <br />the bench run directly below and should be a consideration of the mine operator at the <br />time of final bench excavation. It is apparent that the mine bench face and edges are <br />most sharp and clean when excavated along a line parallel to the foliation and jointing <br />directions. This adjustment to final bench alignment may result in a degree of undulation <br />of the final strike line of the mine bench system, a condition that is favorable to visual <br />harmony (non - linear aspect to final bench line) with surrounding undisturbed terrain as <br />compared to straight lines imposed along the final bench edge. <br />Galena Slope Stability Analysis Discussion and Results <br />While some directional aspects of the granite gneiss material have changed since the <br />1997 investigation, the rock type has remained the same. <br />The Canon City granite gneiss rock type was thoroughly characterized during the original <br />1997 highwall stability investigation, with a number of rock samples subject to <br />geotechnical analysis including unconfined compressive strengths, Tri -axial compressive <br />strengths, and tensile strength measurement performed by the Colorado School of Mines <br />Earth Mechanics Institute Department of Mining Engineering. A copy of test results is <br />included with this report. The results were input to a RocLab program (web- based) that <br />calculates Hoek -Brown as well as Mohr - Coulomb rock strength data. These results are <br />included in this report and utilized to input material parameters into Galena. <br />The Galena Version 6.0 Slope Stability Analysis System was used to analyze the final <br />slope and extent of the highwall feature at maximum build out —up to seventeen benches <br />at 40' height = 680' total vertical height of the mine bench system. Methods of analysis <br />included Bishop Simplified Single Stability Analysis, Bishop Simplified Multiple <br />Stability Analysis, Spencer – Wright Non - Circular and Sarma Analysis covering single <br />bench, multi - bench, and total bench failure surface iterations. A number of results <br />graphics and analytical results pages are included in this report for Division scrutiny. <br />The analytical results show moderate (1.3 or greater) safety factors for all Azurite - <br />designated as well as program- generated failure surfaces. <br />The results graphics and associated analysis sheets are grouped in trials utilizing Bishop, <br />Spencer - Wright, and Sarma methodologies. A seismic co- efficient of 0.15 was used for <br />Spencer - Wright and Sarma methods. Please note that Analysis 7 through 11 for the <br />Bishop runs show a planar surface in lieu of benches, as FOS for #7 is identical to <br />3 <br />