Numerical simulation of moving features of hard roof with three-dimensional discrete element method and nonlinear dynamic analysis

The moving features of a hard roof are studied by three-dimensional discrete element method and nonlinear dynamics; and some conclusions are obtained. The movement of hard roof at the first time is impacted and with high level of stresses; but the system of moving hard roof is an ordered steady state at the phase because value of LE1 is negative. The best chance to prevent rock burst under certain conditions is before the end of the second extracted phase, which can change the movement of hard roof from impact to periodicity. And Sigma(+LEi) states that chaotic degree of the forth phase is the highest according to periodic movement of hard roof, of which the stress level is middle size. Results of the study present that system of moving hard roof is chaotic and producing alteration apart from the first impacted phase.