huainan mining area, confined groundwater, failure depth of floor, numerical simulation, micro-seismic monitoring, Mining engineering. Metallurgy, TN1-997

To reveal the evolution law of the failure depth of the floor under Group A coal seam with regional grouting in Huainan Mining Area, based on the geology and grouting process data of 12123 working face in Pan’er Coal Mine, the mining response under two working conditions of no-grouting and grouting was simulated and analyzed. The failure depth of the floor under different grouting radius was compared. According to the microseismic (MS) monitoring in the mining process, the cluster analysis of its concentration range was carried out by SPSS software. The floor failure from MS monitoring in the adjacent 1612A working face with similar geological conditions and without grouting was discussed. The research showed that, the failure depth of the floor under the grouting condition was significantly less than that without grouting, which preliminarily verified the grouting effect to maintain floor stability. The actual grouting radius in the floor area was 25-30 m. The difference of failure types before and after actual grouting was revealed, and the grouting effect on floor failure was verified again.