Detection of Coal Bust Risk in a Kilometer Depth Workface with Hard–Thick Roof Based on Active–Passive Seismic CT

Practice and theory research proved the “square effect” during longwall mining with hard–thick strata lying on coal seam, which could cause severe underground pressure even dynamic disasters, such as burst; therefore, it became a key area stage that need special attention. The combined active–passive seismic computed tomography (CT) was introduced to detect abutment stress concentration in seam. results of CT inversion show appears early workface ahead theoretical position 50 m 100 significant influencing zone, provides strong guarantee for accurate risk evaluation burst. Precursor information before can be identified based everyday total energy tremors, had period peaks this case. average tremors indicates type belonged foreshock–mainshock pattern. combination events improve accuracy burst danger distinguishing notably. provide worthwhile guidance monitoring prevention hazards similar conditions.