Consideration of strain-bursting phenomena associated with large-scale discontinuities: a numerical study

Mechanisms via which the presence of geological discontinuities (e.g., faults, geological contacts, etc.) may arrest or divert strain-burst related failures of rock masses have been investigated using numerical simulations. The magnitude of energy release has been considered through an estimate of differential displacements and principal stress concentrations. Simulation outcomes suggest that, if coupled with a significant major principal stress decrease, a shallow (e.g., sub-horizontal dipping) fault provides a larger risk of violent release of energy than a steeper orientation. This elevated risk is observed in the simulations to be more pronounced in faults dipping towards the advancing face than faults dipping away from the advancing face. A stress path analysis of the simulation results also reveals that the first exposure location of a discontinuity is the likely location of the highest estimated strain-bursting potential, and that, partially exposed discontinuities result in the highest risk for a violent energy release.