Research on mining-induced failure of grouted rock mass around collapse column based on micro-seismic monitoring

With the gradual depletion of shallow coal resources, the most serious threat restricting the safe mining of Group A coal seams in Huainan Mining Area has changed from gas to floor confined water. According to the production and geological conditions of 12123 working face in Pan’er Mine, a micro-seismic monitoring system was established for the coal floor. Through mining and interpreting micro-seismic data, a micro-seismic identification method for floor failure and conduction induced by mining was proposed. An inversion method of mining fractures evolution was defined based on micro-fractures conductivity. The failure conduction evolution characteristics of grouted rock around collapse column were revealed. The results show that, affected by the advance grouting reinforcement, micro-seismic events show a phenomenon of detour distribution around the grouted collapse column. There was a longitudinal through zone for floor conductivity in the interface and shallow layer, and other areas were sporadically isolated due to the barrier of grouting veins.