Research on occurrence laws of shock bump in horst fault zone of working face

In order to profoundly reveal the particularity of shock bump characteristics, taking Dongtan Coal Mine No. 1305 working face as the research object, the shock bump influence of the second vertical stress distribution and microseismic signal in horst fault zone were analyzed by mechanical calculation, numerical simulatio n and microseismic monitoring. The results showed that the Fault EF93 and the Fault EF32 dislocated sequentially when the coal wall was 84 m and 35 m far from the F ault EF93.Numerical simulation and microseismic monitoring showed that microseismic points always concentrated in front of the coal wall and in behind of the gob, an d mainly concentrated hard rock roof and stress-concentrated area. The high energy shock bump occurred when the coal wall was 80 m far from the Fault EF93 and pro ved the mechanical calculation. The shock energy and times all increased in horst structure zone, fault activation was the main reason of shock increased. There are so me negative correlation between shock energy and b value, so called seismic activity coefficient. It always experiences 'low energy shock concentrated-quite-high ener gy shock happened'before high energy shock bump.