Studies of the spatial and temporal patterns of seismic activity development in the undermined rock mass at the Rasvumchorr Mine

Studies of the spatial and temporal patterns of seismic activity development in the undermined rock mass have been performed at the Rasvumchorr Mine. The main cluster associated with generation of rock caving in the overhang part has been identified. It is established that caving was developing gradually from the depth of the rock mass towards the surface. The results are presented of estimating the quantitative parameters of the seismic process in the undermined rock stratum, i.e. the energy index and the cumulative apparent volume, which reflect the stress changes in the rock mass. Ranges of the stable state of the rock mass, when the overhang rocks do not cave, as well as the ranges of active fracturing and caving of the overhang rocks have been identified. Changes in these parameters for the studied area of the deposit reflect the loading and strength degradation stages in the rock mass. The results of this study correlate well with the data on actual caving of the undermined rock strata. This work is a continuation of the authors' research into the problem of identifying spatial and temporal patterns in the development of undermined rock strata cavings in the tectonically stressed Khibiny massif.