Laserfiche WebLink
Option 2 is characterized by partial filling of the bench <br />r' area at an angle of approximately 15 degrees. This provides <br />II backfill at a point approximately half way up on the excavated <br />(, highwall. Raveling of the material above the fill area is <br />expected, with minor release of large rocks on to the fill area. <br />This condition is identical to the phenomenon on natural slopes <br />' throughout the area. The rock fall is expected to be contained <br />on the 15 degree slope and build up to a level approaching the <br />reclaimed slope of Option 1. When the build up is complete, the <br />final condition will be stable and no further rock fall is <br />expected. The fill required for this option was estimated to be <br />approximately 17,000 cubic yards. <br />Option <br />Option 3 is identical to the condition described in Option 2 <br />with the exception that, instead of allowing the upper portions <br />of the highwall to naturally approach a stable condition, surface <br />protection will be provided to prevent raveling of the material <br />and mechanical supports will be provided for shoring rock to <br />prevent rock fall. The fill required for this option was <br />estimated to be approximately 17,000 cubic yards. <br />It is Rocky Mountain Geotechnical's opinion that the selection <br />and implementation of any of the described options will provide a <br />safe effective means of reclaiming the bench area, and factors of <br />safety against major failure will be greater than or equal to 1.3 <br />for all options. <br />12 <br />