REP28592 - Laserfiche WebLink

Home Browse Search

August 23, 1994 - begin placing toe drain material over the rock drain in the West Pit Excess Fill Area September 8, 1994 - complete placing toe drain material over the rock drain in the West Pit Excess Fill Area September 28, 1994 - quarterly inspection of the West Pit Excess Spoil Fill During the quarter topsoil and organic material were also removed from the West Pit Excess Fill Area. Topsoil removal began on June 17, 1994 and was complete on August 16, 1994. (see photographs 1 through 11) During the quarter the clays were removed from the rock drain area beginning at station 0-30 to station 20+50. Clay removal began on July 6, 1994 and was completed on August 3, 1994. These clays were removed from the drainage bottom until the bottom became hard and layered. On the average, the clay was removed to a depth of about 16 to 18 feet before the bottom became hard and layered. In no place was clay left on the drainage bottom beneath the rock drain area. (see photographs 12 through 15) During the quarter the buttress fill beneath the west Pit Fill Toe was excavated and backfilled and compacted. Excavation began on July 11, 1994 and was complete on July 13, 1994. The excavation was backfilled and compacted beginning on July 14, 1994 and ending on July 15, 1994. The backfill was accomplished by wheelrolling the backfill placed in six inch lifts with a 627B scraper. A dozer, water truck and motorgrader were used to support the scraper, to provide the correct amount of moisture and to place the backfill in controlled lifts. A copy of the material specifications used while building the West Pit Pond is included in this report as the material was similar in nature. During the construction of the West Pit Pond, moisture was maintained near 17% and a minimum of three passes was used while wheel rolling the backfill, and a average compaction of 95% of Modified Proctor density was achieved. During the construction of the buttress fill moisture was maintained near 17% and a minimum of three passes was used for compaction, and as the compaction required for the buttress fill is only 90% of Standard Proctor, the compaction on the backfill will more than meet the construction requirements. (see photographs 16 through 19) During the quarter sorted rock was placed in the rock drain starting at Station 0-30 and by October 1, 1994 was completed to station 9+00. The rock placement began on August 10, 1994 and is currently on-going. Rocks from 1 feet in diameter to 6 feet in diameter were sorted from the locations around the minesite and hauled or pushed into the rock drain system. (see photographs 20 through 29)