Influence of Dislocations on Bumps Occurrence in Deep Mines

The problem of bumps occurrence in deep mines during longwall mining appears to be one of the most serious in the design of engineering of mining. They are caused for various reasons, but basically it is an aftermath of accumulated energy, which is released under some unfavorable conditions. In this paper the influence of given dislocations and their slope in a coal seam are studied based on free hexagon method. This method belongs to a set of discrete element methods and enables one to define and calculate stresses in natural way along the interfacial boundaries of adjacent particles (elements). Since the bumps are connected with a possible slip along the dislocations, dynamical response has to be taken into account. The velocity of excavation of the mine is considered by successive change of values of Eshelby’s forces on the face of the side wall