Pre-evaluation of fault stability for underground mining based on geomechanical fault-slip analysis

Abstract

In underground near-fault mining, fault reactivation is related to many kinds of mine disasters such as mine water inrush, mine earthquakes, gas outburst, rock burst, roof collapse. pre-evaluation of fault stability in the pre-mining phase is of great significance for predicting possible mine fault-related disasters. In this study, based on the geomechanical analysis of fault slip tendency, a technique to the pre-mining evaluation of fault stability under Andersonian stress system was introduced by extending the original Morris’s theory of fault slip-tendency, effects of fault orientation, in-situ stress and pore fluid pressure on fault stability were analyzed. Taking Shilin coal mine as the research background, a pre-evaluation on the stability of all 15 faults distributed in the whole coalfield at the mining depths of 369 and 514 m was conducted, the analysis results demonstrated that all faults in the Shilin coalfield are quite stable at the two mining depths. The work presented in this study is practical and can provide a quantitative geomechanical way in the analysis of pre-mining fault stability and in the risk pre-assessment of fault-related mine disasters.