2012-08-24_REPORT - M1980244 (11)

Home Browse Search

LTM Remediation of Underground Working #4029 and #4031 was performed using a CAT 330 to place coarse shaft backfill material back in the working. The material was placed in small lifts and bucket tamped until access for a CAT 563 vibratory smooth drum compactor was achieved. The material was then placed in 18" to 24" lifts. Each lift was moisture conditioned using a tandem axle water truck (when necessary) and compacted using a 10 -ton vibratory smooth drum compactor, passing over the entire fill surface at least 4 times (method compaction technique was applicable). An AMEC field representative observed the remediation of the underground working. Placement of a three -layer geogrid cap extending 15 feet from the working location identified during confirmatory drilling. Approximately 35,750 square feet of geogrid was placed and accepted by an AMEC field representative prior to select structural fill placement. Approximately 747 cubic yards of select structural fill was then placed over the previously installed geogrid layer in a 6 -inch compacted lift. Prior to compaction the select structural fill material was moisture conditioned using a CAT 773 water truck. Compaction of the select structural fill was then performed using a 10 -ton smooth drum compactor using the static method. Two nuclear density tests were performed with results passing. Moisture - density relations were performed in accordance with ASTM D698 -07. Underground Working #4044 was investigated using a camera, lowering it down the shaft 50 feet An AMEC field representative was present during recording of the video. The video was then reviewed by a CC &V, AMEC, and Ames representative. No laterals were identified in the working to a depth of 50 feet. Remediation of Underground Working #4068 was performed with the placement of a three -layer geogrid cap extending 15 feet from the working location identified during confirmatory drilling. Approximately 4,800 square feet of geogrid was placed and accepted by an AMEC field representative prior to select structural fill placement. Approximately 100 cubic yards of select structural fill was then placed over the previously installed geogrid layer in a 6 -inch compacted lift Prior to compaction the select structural fill material was moisture conditioned using a CAT 773 water truck. Compaction of the select structural fill was then performed using a 10 -ton smooth drum compactor using the static method. Two nuclear density tests were performed with results passing. Moisture - density relations were performed in accordance with ASTM D698 -07. Underground Working #4069 was investigated using a CAT 330 excavator and observation was performed by an AMEC field representative. Excavation of the area was performed and it was found to be a shallow surface working. The native material was found to be consistent and all signs of a significant working were removed. The working was backfilled with structural fill in 18" to 24" lifts using various CAT dozers. Each lift was moisture conditioned using a tandem axle water truck (when necessary) and compacted using a 10 -ton vibratory smooth drum compactor, passing over the entire fill surface at least 4 times (method compaction technique was applicable). Underground Working #4070 was investigated using a CAT 330 excavator and observation was performed by an AMEC field representative. Excavation of the area was performed and it was found to be a shallow surface working. The native material was found to be consistent and all signs of a significant working were removed. The working was backfilled with structural fill in 18" to 24" lifts using various CAT dozers. Each lift was moisture conditioned using a tandem axle water truck (when necessary) and compacted using a 10 -ton vibratory smooth drum compactor, passing over the entire fill surface at least 4 times (method compaction technique was applicable). MEW Weekly Report WE 03.17.2012