Assessing the contribution of seismicity to the demand on ground support elements at LaRonde mine

Abstract

Seismic activity is known to affect the short-and long-term behaviour of mining ground support, yet the influence of seismicity on ground support demand is not fully understood. This paper quantitatively assesses the influence of various seismic parameters on the performance and degradation of ground support elements. A large database was created using the LaRonde mine (Quebec, Canada) as a case study, which consolidates information on the history of the rock support of an entire mine sector comprising 18.5 km of drifts: type, installation date, and behaviour over time. This database was linked with the seismic event database available at the mine. Analyses identified various seismic parameters (i.e. large seismic events, number of seismic events, increase in apparent stress, b-value from the Gutenberg-Richter frequency-magnitude relationship, peak particle velocity, and energy radiated from the event) as precursory trends that may influence the performance and degradation of ground support elements. A key finding is that the number of seismic events and their magnitude are contributing factors in controlling the demand on ground support. A high number of seismic events and high local magnitude event have frequently been recorded before observing degradation on ground support elements. Another important finding is that the demand on ground support cannot be explained entirely by seismicity; it is also controlled by other site factors.