Geomechanical evaluation of deep-level robotic coal mining by the results of numerical modeling

Abstract

It is of the current concern to develop a robotic technology for deep-level coal mining in the conditions of high methane content, gas-dynamic events and spontaneous firing. Such conditions increase rate of accidents which engender the health of miners. With a view to preventing accidents in coal mines, geomechanical evaluation of process requirements to be imposed on engineering, manufacture and introduction of robotic mining facilities for deep-level coal beds without the presence of personnel in hazardous areas has been accomplished. 3D numerical modeling is carried out with the finite element method and the author’s set of problemoriented programs. By the results of the simulation exercise, it is found that in the shortwall mining, the vertical subsidence of roof rocks grows almost linearly with the mining depth. The most hazardous areas in the shortwall roof are the junctures of breakage heading and rooms. The areas of maximum concentration of the vertical stresses in coal bed in the zone of operation of cutter–loader cutting head are detected. The stresses in these areas exceed coal compression strength, which allows utilizing energy of rock pressure to break coal at the minimal addition energy transfer to the cutting head, at the decreased amount of metal per structure of the robotic device and at the minimal energy consumption of coal extraction. The shortwall parameters and the process requirements applied to robotic systems of deep-level coal mining are substantiated.