Prediction of stress concentration areas in rock mass by the data on P-wave velocities in regional rockburst hazard prediction using the microseismic method

This article discusses the influence exerted by the stress–strain changes on the P-wave velocities in rock mass using the microseismic method. The study was carried out at the Komsomolsky and Skalisty Mines. The estimation of the interrelation between the P-wave velocities and seismic events shows that the increase in the wave velocity before seismic events is connected with the stress redistribution in rock mass and after seismic events—with the rock destressing. The microseismic monitoring of the P-wave velocities demonstrated efficiency in detection of stress concentration area, especially in case of low seismic activity. However, the rockburst hazard prediction by the criterion F was limited in the mines with low seismicity. Nonetheless, the method allows prompt detection of potential hazards and compliments the regional-scale rockburst hazard predictions. The recommendations are given for the method application toward higher safety in mines, including rock mass stabilization technologies such as filling of voids and injection of rock mass, which minimizes risks of rock bursts. This approach to the analysis of changes in the stress–strain behavior of rock mass is an important supplement to the conventional stress–strain assessment of rock mass and can be integrated with the other methods of geomechanics and seismology. The method is of special value when the level of seismic activity is insufficient for providing reliable statistics on the parameter F, which limits application of conventional prediction. The obtained data allow early identification of local changes in rock mass condition because of elastic stress concentration, which improves accuracy of regional rockburst hazard prediction. This is important in planning and implementation of mining operations in areas of high geodynamic activity, and in elaboration of measures on prevention of accidents and on work safety in underground mines.