Investigation of Fault Displacement Evolution During Extraction in Longwall Panel in an Underground Coal Mine

A physical simulation model is constructed to study the characteristics of fault displacement evolution at Yima mining area, Henan Province, China. The geological condition at Yima mining area is complicated with high in situ stress, reverse faults and extremely thick conglomerate rock strata. In this study, the fault movement process during extraction of a coal seam is simulated and the precursory information on the fault slip is investigated. The fault displacement and shear stress, as well as the fault slip location are monitored in the simulation using digital speckle image correlation method, shear stress sensors, and acoustic emission monitoring. The investigations reveal the following: a relatively long suspension prior to the sharp increase in acoustic emission events might be used as the precursory information on an impending fault slip; the combined effect of the fault slip and extremely thick conglomerate rock strata may induce coal bursts; the interaction zone of thick conglomerate rock strata and fault structure is a high-risk region that can induce fault slips.