Inversion of seepage channels based on mining-induced microseismic data

Abstract

Water inrush in mines has always been a major technical problem restricting the safe production of mines with abundant water. Seepage channels formed by fractures in rock masses provide the necessary conditions for water inrush to occur. Effectively controlling the formation of fractures in rock masses is essential for preventing water inrush disasters. In response to the shortcomings of conventional water inrush monitoring methods, a set of methods for the inversion of seepage channels in rock masses based on mining-induced microseismic (MS) data was proposed in this paper. A discrete fracture network (DFN) was built based on moment tensor (MT) theory, and a method for extracting reasonable fractures associated with different failure mechanisms was proposed. To enhance the applicability of the fractures derived from MS data (MS-derived fractures), the MS-derived fractures were transformed into a graph structure by graph theory. Subsequently, the hydraulic properties of each node and edge in the graph structure were obtained based on Darcy's law. In addition, the fluid flow time in the MS-derived fractures was weighted to detect the shortest seepage channel. Finally, the method was applied to a mine that experienced a water inrush disaster. The seepage channel formation process, water pressure distribution and main seepage channel in the study area of the mine were analyzed. The results may provide references for decision-makers regarding when and where to implement water shutoff measures in mines.