ABSTRACT
Longwall extraction, in conjunction with caving, is one of the most widely practised underground coal mining methods. Caving and the subsequent reconsolidation of the caved rocks combine to form a mechanism which is kernel to the solution of several important problems. First, the caving and reconsolidation processes are explored, assuming that the roof mass is reasonably ‘uniform’ in the sense that each stratum is ready to conform with the deflection of layer beneath it. Next, the influence of a massive bed on the process of caving is probed. Experience shows that once the extracted span is fairly large, the caving, recompaction and the lowering of the upper beds often progress in repeatable cycles in concert with the advance of the face. The caving mechanism may prove to be an effective means of investigating rock mechanics problems associated with long-wall mining. Further studies and back-calculations are required to explore the utility of the approach in the solution of practical problems.
