Geomechanical justification of geotechnical situation in coal extraction with highwall mining system

One of the most effective approaches to reduction of coal loss in open pit within ultimate limits is extraction of coal reserves from the pit walls and bottom using the highwall mining systems. The high efficiency of the method is conditioned by minimal capital cost and reuse of the existing geotechnical infrastructure. On the other hand, the safe application of this approach depends on the rock mass quality. In mining practice, the major application area of the highwall mining systems is pitwall rock mass of damping jointing. In this connection, this paper aims to estimate influence of rock mass quality on stability of pit wall and underground openings (rooms and pillars). The set problem is solved by the finite element modeling of geomechanical situation for standard conditions of an open pit coal mine. The novelty of the research consists in more comprehensive inclusion of rock mass lithology, jointing, deformation and strength characteristics, initial stress state and structural features of technology in the problem solution.