ABSTRACT
The article discusses geomechanical aspects and numerical simulations associated with the mining methods dedicated for flat or flatly dipping orebody, i.e. room-and-pillar and longwall mining systems with regard to development of hypothetical mining panel. It was assumed that the overburden strata consists of several homogeneous rock plates reflecting the typical lithology in the Lower Silesia area. The results of the computer 3D simulations permitted elastic-plastic rock mass stability analysing, identifying the areas being more susceptible to damage. Each model has been analysed from the point of view of different methods of roof control. The geomechanical risk assessment procedure utilized so called safety margins which were defined as a distance between the point characterized by the actual local strain/stress conditions and the instability (limit) surface(s) which location in the 3D stress/strain space could be determined using different strength theories. The obtained results have proved that in the considered geological conditions, room-and-pillar approach has a significant advantage from point of view geomechanical safety, over the mechanized longwall excavation system.
