Stress evolution and induced seismicity in mining: Lab test, observation and modeling

Comprehensive approach to reconstruction of stress fields in rock mass at any stage of mining was offered and realized for Zapolyarnaya coal mine. The approach involves laboratory tests of rock for determining the empirical dependency of longitudinal velocity on stresses, the straight-ray tomography taking impulses of dynamic events as the sounding signals, and the solution of inverse problem where the input data is the velocity field reconstructed by tomography. Procedure of the joint analysis of stochastic and deterministic information, which allows finding relationships between the parameters of various physical fields was substantiated in a lab environment and tested in terms of Tashtagol iron-ore deposit. Correlation analysis of space-time distribution of induced seismicity parameters and stresses in mined object permits to relate the variation of stress field characteristics and the number of seismic events in different parts of an object. This provides a way to predict the induced seismicity parameters in the course of mining.