Mechanisms of Foreshocks and Seismic Hazards Under Mining-Induced Stress in Longwall Mines
摘要
Understanding seismicity hazards in longwall mining is critical for the safety and operational efficiency of mining activities. This paper explores the application of foreshock theory from seismology to analyze high-energy seismic hazards (mainshocks) within a mining context. By identifying the magnitude, location, occurrence time, and radius of mainshocks, along with their preceding foreshock episodes, this study provides insights into the seismic behavior associated with longwall mining. The research identifies both cascading and pre-slip mechanisms of foreshock episodes, where the former are discerned through changes in Coulomb failure stress, and the latter through spatial positioning and waveform similarities. Furthermore, the analysis extends to the examination of local secondary stresses in longwall panels (stress concentration ahead of longwall panel), finding that seismicity events tend to cluster in areas of stress concentration, irrespective of variation in Coulomb failure stress. The seismic events also show evidence of fluid inrush with the occurrence of mainshocks by examining spatiotemporal distances between seismic events, variations in Coulomb failure stress and local secondary stresses. Research outcomes not only enhance the understanding of mining-induced seismicity but also provide a basis for developing improved predictive models for seismic risk management in mining operations.