Analysis of geomechanical changes in hanging wall caused by longwall multi top caving in coal mining

Abstract

The method of sublevel coal extraction requires multi caving of the hanging wall layers, which are recompressed, and where each represent a hanging wall in sublevel stoping. Extensive stress and deformation changes in the surrounding area and in the mine represent a safety hazard for employees since the supporting system in the mine roadway could collapse. By accepting geomechanical principals in following caving processes in underground coal mining with the Velenje mining method in above ground acquisition, there are mutual connections made, between the geomechanical parameters of the occurring geological materials in connection with the intensity of coal mining. A numerical model, which allows for in-depth analyses of the geomechanical processes which occur in the hanging wall, the footwall, and in the coal seam during sublevel coal excavation, is broadly applicable and highly relevant for analyzing the intensity and the level of caving processes in sublevel coal mining, and for making realistic plans for coal excavation with worker safety in mind.