Application of discrete element methods to fracture mechanics of rock bursts

In deep mining engineering sudden release of accumulated potential energy occurs under special conditions. This phenomenon is known as bumps or rock bursts. During the bumps the rock turns out to grain material, which bursts into a free space. The mathematical and experimental modeling requires very attentive treatment. Two methods put forward in this paper can serve a mathematical toot for solving such problems. The first, discrete hexagonal element method can be considered as one of discrete element methods (DEM), which are very often used in mechanics of granular media. They substitute the methods for solving continuum problems. The great disadvantage of the classical DEM, such as the particle flow code-PFC (material properties are characterized by spring stiffness), is to feed them with material properties provided from laboratory tests (Young's moduli, Poisson's ratio, etc.), which are not quite consistent with stiffnesses of springs, the PFC requires. This is why we utilize the principal idea of the DEM, but cover the continuum by hexagonal elastic, or elastic-plastic elements. In order to complete the study, other DEM is discussed and numerical results of both methods are compared with experiments in scale model. (C) 2003 Elsevier Ltd. All rights reserved.