Stress relief jointing in eastern Kentucky.
Rock Mechanics: Contributions and Challenges: Proceedings of the 31st U.S. Symposium, June 18-20, 1990, Colorado School of Mines, Golden Colorado. Hustrulid WA, Johnson GA, eds. Brookfield, VT: A.A. Balkema, 1990 Jan; :439-446
This paper is the result of a Bureau of Mines program to characterize roof conditions near outcrop in drift coal mines of eastern Kentucky. Joints occur throughout the shallow overburden of eastern Kentucky, separating the strata in blocks or wedges. Except for bedding planes, they are the most important structural feature in the characterization of shallow rock mass in the region. Unweathered, intraformational joints were common in the study area. No easily recognized regional joint systems were identified. However, highly weathered joints that are vertically continuous through various rock types, but spatially limited to areas near outcrop, were present in almost every drift mine examined. The orientation of these weathered joints was not consistent with the regional tectonic pattern, putting their origin and significance in question. Three underground sites were examined and four surface sites with large, unweathered outcrop exposures, were selected for detailed observations to resolve the geologic character of these joints.
Rock-mechanics; Geology; Structural-analysis; Coal-mining; Underground-mining; Surface-mining; Surface-properties; Ground-control; Ground-stability; Safety-monitoring
OP; Conference/Symposia Proceedings
Rock Mechanics: Contributions and Challenges: Proceedings of the 31st U.S. Symposium, June 18-20, 1990, Colorado School of Mines, Golden Colorado