3D Stress-Ratio-Based Method on the Tendency Analysis of Mining-Induced Fault Reactivation

In underground mining, sudden fault reactivation is the root cause of many types of mine disasters, including mine seismicity, water inrush, roof collapse, and gas outburst. The accurate assessment of the risk of mining-induced fault reactivation is important in disaster prevention in near-fault mining. In this study, based on the stress ratios of the three principal stresses under the Andersonian stress state, we introduce a new mode for defining the stress regimes and a new 3D stress-ratio-based approach for the tendency analysis of fault reactivation by extending the original Morris's theory of fault slip-tendency. Our analyses showed that the reactivation tendency of a fault in a stress field is correlated with the stress ratios, whether the correlation is positive or negative depends on the stress regime of the stress field. Considering the abutment stress effects in front of the working face, an approach to the tendency analysis of mining-induced fault reactivation is also proposed using the stress-ratio-based algorithm. Taking the No. 8101 mining face of the Wangzhuang mine as the engineering background, a case study is presented to demonstrate the application of our proposed method in actual mining practice for predicting the risk of fault reactivation. The proposed method is a practical technique and can be applied widely for any mining methods, stress regimes, and fault orientations.