Hybrid Discrete Element Code for Simulation of Mining-induced Strata Movements.
Dem 1st U S Conf on Discrete Element Methods Csm Press :10 pages
To simulate the kinematics associated with mining-induced subsidence in a blocky rock mass, the U.S. Bureau of Mines developed a hybrid rigid block model by combining a small displacement code with a large displacement code. Gravity was applied to a rigid block mesh using an implicit formulation, and the equilibrium displacements were then used as initial conditions for an explicit analysis in which excavation of a longwall mine panel and subsequent subsidence were simulated. A parameter study was performed to evaluate the influence of rigid block contact stiffness, vertical joint density, and contact roughness on mining-induced strata movements for comparison with previously obtained field measurements. The best agreement between measured and calculated displacements was obtained when a relatively low stiffness value was maintained constant for all contacts. A surprising result was that neither increasing the density of vertical joints nor reducing the rigid block contact roughness improved the agreement between measured and simulated displacements.
Dem 1st U.S. Conf. on Discrete Element Methods, Csm Press