Anatomy of mining-induced fault slip and a triggered rockburst

Abstract

Fault slips and triggered rockbursts pose a significant threat to the safety of mining personnel and infrastructure in deep coal mines. Sudden and dynamic slip may occur along a pre-existing fault characterized by the presence of contact between two opposite faces. Such slips are capable of changing the balance of forces when mining activity is conducted in the area surrounding the fault at depth and are accompanied by energy release that has the potential to cause serious damage to roadways and working faces. The aim of the comprehensive investigation reported here was to elucidate the evolution of the stress field surrounding a fault due to mining activity in adjacent working faces, using Fast Lagrangian Analysis of Continua in 3 Dimensions (FLAC3D) numerical simulations, especially variations the high shear stress area. We then proposed the mining-induced fault slip mechanism. The evolution rule of sources during fault slip could be clearly explained using field microseism (MS) monitoring data, and the correlation between source parameters (e.g., static stress drop, peak particle velocity, and displacement) and fault slip was established. Correspondingly, the multi-parameter precursors of a rockburst induced by the fault slip were analyzed and summarized in detail. This work provides a number of reference points to be used for the warning and controlling of rockbursts triggered by fault slip in coal mines.