Factors influencing intersection stability in U.S. coal mines.
Molinda G; Mark C; Bauer E; Babich D; Pappas D
Proceedings of the 17th International Conference on Ground Control in Mining, August 4-6, 1998, Morgantown, West Virginia. Peng SS, Holland CT, eds., Morgantown, WV: West Virginia University, 1998 Aug; :267-275
Groundfalls are much more likely to occur in coal mine intersections than in entries. NIOSH is using the experience of U.S. coal mines to determine the factors which influence intersection instability and provide guidelines for the safe excavation and support of intersections. Detailed field investigations have resulted in a database of U.S. coal mines containing 12 mines and 639 roof falls so far. By using the roof fall rate as the outcome variable, correlations between roof geology (CMRR), intersection span, and roof support have been established. Case studies have indicated that replacing 3-way intersections with 4-way intersections may not reduce the total number of roof falls. Additionally, the size of intersection spans tend to decrease with lower (weaker) CMRR. Protocols have been established for the collections of roof bolt parameters. The performance of individual roof bolts can now be tracked with roof fall rate.
Coal-mining; Mining-industry; Roof-falls; Underground-mining; Miners; Mine-workers; Mine-safety
National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory, P.O. Box 18070, Pittsburgh PA 15236
Peng SS; Holland CT
Other Occupational Concerns
Proceedings of the 17th International Conference on Ground Control in Mining, August 4-6, 1998, Morgantown, West Virginia