Safety in Substoping-and-Caving in Tectonically Stressed Rock Masses

Abstract

Mining of a thick steeply dipping deposit using sublevel caving with end-face ore drawing in transition from open pit excavation to underground mining is considered in conditions of developed tectonics. The technology was justifed by mathematical modeling of the stress state of the rock mass using finite element method. Safe parameters of the mining system were determined by solving a variational problem with a variable degree of geomedium disturbance in the existing mining and engineering structure when depleting reserves at an advanced stoping stage. The predicted areas of stability losses for main structural elements of the mining system have been determined. Safe parameters of ore breaking and drawing were calculated using the stability condition of mine workings. Recommendations are given for the excavation of thick steeply dipping deposits under open pit mining.