Prediction of bump hazards associated with coal mining under competent roofs

A quantitative parameter, the released strain energy, is proposed as a predictive index for the likeliness and severity of coal bumps associated with mining under competent roofs. The strong roofs are modeled as either cantilevering or bridging elastic beams over continuous elastic foundations subjected to an exponentially distributed vertical stress. Based on previously developed analytical methodology, major factors affecting strain energy storage are identified and analyzed. Criterion for pressure and shock bumps are suggested. Two case studies from U.S. bump-prone mines show that the theoretical predictions are in close agreement with the field data.