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Mining Publication: Factors Influencing Intersection Stability in U.S. Coal Mines

NOTE: This page is archived for historical purposes and is no longer being maintained or updated. Contact NIOSH Mining if you need an accessible version.

Original creation date: August 1998

Image of publication Factors Influencing Intersection Stability in U.S. Coal Mines

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.

Authors: GM Molinda, C Mark, ER Bauer, DR Babich, DM Pappas

Conference Paper - August 1998

NIOSHTIC2 Number: 20000095

In: Proceedings of the 17th International Conference on Ground Control in Mining, Peng SS, ed., Morgantown, WV: University of West Virginia, 1998 Aug; pp. 267-275