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It is generally accepted as state-of-the-art in soil engineering <br />today that a factor of safety on the order of 1.5 is considered accept- <br />able for the .long term stability design of cut slopes and fill slopes. <br />The factor of safety is defined as the sum of the resisting forces <br />available to prevent large-scale mass movement divided by the sum of <br />the driving forces acting to promote large-scale mass movement. Theor- <br />etically, such a movement would occur when the two forces became equal, <br />or the factor of safety equals 1.0. Therefore, theoretically any <br />slope for which the factor of safety exceeds 1.0 should not fail. How- <br />ever, such a condition leaves little margin for error. In the case of <br />restoring high wall areas to their approximate original contour, as <br />is the case in this particular project, Regulation No. 4.14.2 (1)(B) <br />of the Colorado Mined Land Reclamation Board requires that a minimum <br />static factor of safety of 1.3 be achieved. <br />RESULTS OF ANALYSIS - CONCLUSIONS AND RECOMMENDATIONS: <br />Results of all analyses performed will be found in a Table of <br />Stability Analysis Results in the Appendix of this report. The <br />location and orientation of critical failure circles and critical <br />shear surfaces for the various alternatives considered will be found <br />on the Cross-Sections in th.e map pocket in the: Appendix of this <br />report. In all cases, the potential for both circular failures and <br />wedge and/or plane failures was analyzed. Specified shear surfaces <br />for analyzing wedge or plane failures were arbitrarily selected and <br />typically range from as little as two to as many as five different <br />wedges for each section analyzed. <br />As may be seen from the stab-lity analysis results for the <br />existing condition of high wall and bench fill embankment with no <br />-9- <br />