Numerical investigation of impacts of geological faults on coal burst proneness during roadway excavation

Geological structures such as faults and dykes are one of the main contributors of catastrophic rock and/or coal burst events in underground mines. This study focuses on the impacts of faults on burst proneness in development roadways using the Universal Distinct Element Code (UDEC). A sensitivity analysis on the influence of fault proximity to a roadway showed that faults located at a critical fault proximity to the roadway can generate substantially high level of total radiated seismic energy and peak kinetic energy magnitudes. In addition, a parametric study investigated the effects of fault dip angle and mining depth on energy release characteristics of faults positioned at the critical proximity during a roadway excavation. The results were compared to a base, ‘no-fault’ model to assess and distinguish the modes of energy release. Numerical modelling results revealed that, for all fault dip angles, the total seismic energy and peak kinetic energy magnitudes increase rapidly as the mining depth increases and can reach more than double the magnitudes resulted from the no-fault models. The numerical analyses have also shown that unfavourably positioned geological faults may play a major role in the release of a substantial amount of strain energy when interacting with excavations.