Development of criteria due to seismic risk for temporary closing/re-opening of seismically active mines

Purpose and goal

Seismic events in the mines may cause severe damage and expose personnel in the mine at risk and potentially loss of life. Criteria and practical approach and rules for closing specific areas in mines in case of increased seismic hazard and risk could help to reduce the risk and increase the safety. The aim was to define these cases based on the worldwide experience and to develop methodologies and derive empirical relationships and parameters that could be used for developing practical rules for specific cases based on seismicity, stress and seismic wave velocity changes.

Expected results and effects

1) New approach for estimation of spatial distribution of aftershocks of large events 2) New approach for prediction of the temporal development of aftershock series 3) Empirical relations for the seismicity after large seismic events and blasting (duration and extend) 4) Empirical relations between small-scale variation of the in-situ stress and large seismic events 5) New approach for monitoring of velocity changes in relation to large seismic events with new empirical relations 6) New software for automatic seismic source parameter estimation with uncertainties

Planned approach and implementation

The work was related to cases related to increased seismic hazard: before and after large seismic events and after production blasts Methodological work with software: 1) approach to define the extend and duration of aftershocks series (large events) with testing on real data 2) analysis of in-situ stress data and correlation with large seismic event and production 3) approach for using time-lapse tomography for monitoring of seismic velocity changes before and after large seismic events Empirical studies: Seismicity behavior after large seismic events and after blasting