An ongoing hazard to safety and production exists in the potential for sudden failure of underground room and pillar mine workings. In order to better understand these events, the study of instability must encompass brittle material behavior and the capacity for sudden displacements in the overburden. This paper presents the results of a case study in which the 5.3 local magnitude seismic event associated with a documented mine collapse is correlated with the results of a numerical simulation through calculations of released kinetic energy. The approach includes a calibration of strain softening properties at the pillar scale to accommodate an unstable response and match deformations observed at the time of the collapse. Widespread pillar failure is then simulated in a mine scale model using a 2D finite difference software. Calculations of released energy are recorded throughout the simulation, and the results are compared to estimates of released energy associated with the seismic event through empirical relations. The analysis shows that the sudden reduction in average support pressure observed at the pillar scale accommodates a release of energy in the overburden of the mine scale model that correlates well with the documented seismic magnitude. The method of analysis illustrated in this study may be useful in future studies concerning the potential for unstable pillar failure.
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