Retrospective analysis of seismicity as a planning tool to reduce risk


Sandra Smith, Cementation Canada Inc.

Understanding the rock mass response to underground mining is a significant benefit to assist with decisions aimed at maintaining safe access and controlling conditions in which incidents of rock mass failure may occur during excavation development.  As Canadian mines get deeper, high stress conditions become more prevalent, often leading to dynamic rock mass failure.  This failure results in recordable dynamic stress waves related to mining induced seismic events.  The occurrence of large seismic events has become commonplace in many deep hardrock mines. This discussion outlines the investigation of mining-induced seismic events recorded in deep mining with a focus on events occurring between 2000 and 3000 metres below surface.  Spatial and temporal trends of large seismic events are investigated with particular emphasis on analysis of the variations in radiated seismic energy associated with large magnitude events. Through analysis of seismic source parameters such as radiated seismic energy, a better understanding of dynamic rock mass failure in a mine can be achieved.  This improved understanding provides a basis for future mine planning design and aids in managing the risks associated with deep mining in high stress conditions.