ABSTRACT
Unstable failures of rocks underground are known to occur on occasions during various energy and resource extraction activities. Examples of relevant unstable failures include rock bursts encountered in mining and construction excavations, earthquakes induced by geothermal energy extractions, and deep wastewater disposal. This paper presents numerical modeling methodologies for estimating magnitudes of energy components during unstable failures. A rectangular tabular excavation supported by a single mine pillar is simulated to demonstrate the unstable failure of brittle rock in compression. The brittle response assigned to the pillar surrounded by a soft loading system results in events with highest magnitudes within 3% of expected graphical values. We model a strike-slip fault and simulate dynamic rupture restricted to energy available and consumed during the rupture. Numerical calculations of the rupture length, average slip (shear displacement), and kinetic energy are shown to be within 5% of the existing analytical solutions.
