2018-05-25_PERMIT FILE - M1995004 (4)

Home Browse Search

GEOTECHNICAL STABILITY EXHIBIT This information is presented to address the plan to mine within 200 feet of the structures listed in ExhibitS. This is a dry mining operation so no water is associated with the mine . There are two structure owners for which there was no damage agreement received. Both are 3 strand wire fences, the southern one is owned by the State of Colorado Parks and Wildlife (CPW) and the fence on the west is owned by the BLM. This Stability analysis is being done to save time in case we do not receive the agreements that will be mailed to the structure owners within 200 feet of the permit area . The information presented is based on the cross sections A-A' and B-B' shown in this report and using the distances from the fences to the closest mining area to determine if safety factor calcula- tions are needed for the proposed mining face closest to the structure . The location of the Cross Sections can be found on the Map Exhibit C-1 -Mining Plan Map. The mine depth closest to any structure where no waiver agreement has been obtained is 50 feet . This in the CPW fence line that lies approximately 425 feet south of the top of the reclaimed 3 : 1 slope in the southwest corner of the mine and no mining will take place within 200 feet of this structure . Mining is complete on the south end so this fence will not be impacted in the future . Section A-A' shows the relationship of the CPW fence to the floor of the mine and reclaimed slope . The overall slope from the toe of the reclaimed slope to the fence is 9 . 4h to lv. As shown on the Map Exhibit F - Reclamation Plan Map, the f loor of the mine will daylight out on the west side of the mine leaving a gentle sloping floor at the same elevation or slightly above the west fence . In this area the working face will be perpendicular to the fence so no highwall will face the structure . There will be no excavation below the fence elevation and therefor no excavated slope to fail along that side . When the mining face in this area, reaches the final floor elevation, the toe of the mine face will be 25 feet from the closest point on the BLM fence and will slope up the existing hill side at a rate of 7h to 1V for 245 feet to the east . The final east face will be graded 3h to lv as mining progresses and the toe will be 440 feet or more from the fence . No safety factor was calculated for this area since mining will be above the structure and the final reclaimed slope will be over 200 feet from the BLM Fence . Along the working face the overall natural slope averages 8 . 1h to lv. 69