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<br />1 <br />5-01. GENERAL <br />V. RECOMMENDATIONS <br />' Reconfiguration of the slope on the east side of the Central Pit was based on the following goals: <br />~ Obtain a stable and safe slope, <br />' ~ minimize visual impacts by lowering the eastern ridge only as much as necessary to achieve <br />stability and safety, <br />' ~ configure the final slope to fit into present mine reclamation requirements and plans, <br />' ~ configure the slope to fit with present mine development plans, and <br />~ allow for construction procedures consistent with mine operations and mining equipment <br />' presently in use at the Morrison Quarry. <br />It is our understanding that significant lowering of the ridge immediately east of the failure area could <br />result in undesirable visual impacts when the quarry is viewed from the east. Therefore, it is <br />' desirable to lower the eastern ridge only as much as absolutely necessary. In order to accomplish this <br />objective, Haley & Aldrich recommends a two phased approach in which phase one stabilizes the <br />present slope and lowers the ridge as little as possible. The behavior of the slope could then he re- <br />' evaluated to evaluate the need for additional stabilizing measures, if necessary, during phase two. <br />Phase one which is stabilization of the present slope and is termed the interim configuration, <br />comprises the design presented in this report. <br />Design of the interim configuration incorporates, to the degree practical, present mine topography and <br />mine operations. Highwalls are 40 R high which is half of the standard 80 R highwall height <br />' typically used in the mine and corresponds with standard drill and blast depths. <br />Haley & Aldrich recommends that the failing slope he remediated in a step-wise fashion to: First, cut <br />' to the interim slope reconfiguration as described above; secondly, collect additional geologic data and <br />evaluate slope performance; and lastly, reassess slope and bench stability and safety. At this point the <br />need to change overall slope angle, related impacts, and safety can he re-evaluated. This step-wise <br />' approach is recommended to redesign a slope having the minimum disturbance to the ridge, and <br />therefore, the minimum visual impact of the quarry. Also, exposure of the slope as shown for the <br />interim configuration will allow for collection of a larger data set on rock joint orientation, the <br />' location and character of the inferred fault or shear zone, and the possible intersection(s) of existing <br />failure planes with highwalls. <br />' Design of the interim reconfiguration is presented in a set of drawings labeled sheets 1 through 10 of <br />10, depicting the recommended slope reconfiguration in detail in plan and profile views. Sheet I <br />illustrating the reconfigured slope in plan view is included in this report; the entire drawing set has <br />been presented independently of this report. Sheets I and 2 are plan views showing an overview and <br />t detailed plan view, respectively, of existing and proposed new topography. These two figures are <br /> <br /> <br />