Abstract
Geotechnical strategy to resume mining following a significant seismic event - Westwood mine case - (+3.7 MN Westwood-bang).
A +3.7 MN seismic event occurred on October 30th 2020, at Westwood mine, Following the event, the entire mine production was halted to focus on understanding the mechanism of the event and to identify areas with potentially similar conditions. The current paper tends to present the background information that was available prior to the event, Subsequently, the investigations were carried out to understand the mechanism of the seismic event, the investigations include: geological, structural and geotechnical model updates, advanced seismic analyses, numerical stress modelling, integrated rock burst hazard assessment, as well as a complete review of the dynamic ground support standards of the mine. Finally, a very detailed risk register was prepared to identify ground control related hazards and to establish a mitigation measure plan process (i.e., risk identification, existing mitigation measures, current hazard levels, proposed mitigation measures as well as residual hazard levels).
A strategy was developed to thoroughly investigate the mines’ seismic and geotechnical behaviors and develop mitigations to safely reopen the mine.
This aim of this paper is to present the following
- The methodology of the investigation
- Some of the results of the investigation
- The mitigation actions to resume safe mining operations at the mine