STUDY OF ROOF CAVING IN THE EASTERN U. S. COALFIELDS.

Appropriate roof control is the most important requirement in underground coal mining and, in the case of longwall panels or second mining in room and pillar extractions, this can be simply expressed in terms of good and predictable roof caveability. The objective of this study is to analyze caving and mass deformation characteristics above longwall panels in Appalachia. Some of the topics covered include analysis of the effects of the geological and geomechanical characteristics of the strata on the caving height and the bulking of the caved material; and testing of the applicability of the various theoretical and empirical models of roof caving.