Evaluation of fault-slip potential due to shearing of fault asperities

Mining activities in underground mines could induce fault-slip that inflicts devastating damage to mine openings. Thus, enhancing current knowledge about fault-slip taking place in underground mines is of paramount importance. In this study, static and dynamic analyses are performed using mine-wide models encompassing a fault running parallel to a steeply dipping, tabular orebody. In the static analysis, modelled stopes within the orebody are extracted and backfilled in accordance with a sublevel stoping method. Dynamic analyses may be performed, depending on the stress states at the end of each mining stage during the static analysis, to simulate fault-slip induced by a stress drop resulting from asperity shear. Selected seismic source parameters of the simulated fault-slip are then computed for each mining stage. The relation between D/H (where D is distance between the fault and the orebody, and H is height of the mined-out ore) and seismic source parameters is examined. It is shown that seismic moment and radiated seismic energy correlate well with D/H, thus suggesting that this ratio could be used as an indicator of fault-slip potential. On the other hand, no noticeable correlation between the maximum slip rate during fault-slip and D/H could be ascertained.