Cutter Roof Failure: Six Case Studies in the Northern Appalachian Coal Basin

摘要

The Bureau of Mines report presents the results of engineering and geologic investigations conducted in six coal mines affected by cutter roof failure. The studies were conducted to gain a basis for recommending methods to predict and prevent the occurrence of cutter roof failure, a common ground control problem in mines of the Northern Appalachian Coal Basin. Three distinct factors were found to be initiators of cutter roof failure: high horizontal roof stress; surface topographic variations; and geologic anomalies. Effective control of cutter roof was obtained through improved bolting techniques, entry and mine reorientation, and entry and pillar size modifications, but only when selected based on the actual cause of failure.