Experimental Study on the Failure Characteristics of Strata With Different Filling Rates in Long-wall Filling Mining

In order to study the mechanical characteristics including deformation, displacement and stress distribution of surrounding rock during the process of filling mining with different filling rate, according to the geological and mining conditions of the 12307 working face in some coal mine, the analyses of simulation were synthetically applied. The results show that the deformation and failure of overburden rock is closely related to the filling rate, when the filling rate is low, the fractures are extensive, longitudinal and transverse fractures are staggered, the vertical displacement of rock strata is differentiated obviously,while filling rate is high, the fractures appeared only in low strata, the rock strata displacement main occurs near the immediate roof, the strata displacement curves in the stable subsidence area are almost together, the rock presents the overall bending deformation, from the roof to the surface layers are whole movement characteristics. There is a power function between the influence distance and the filling rate, the concentrated stress decreases linearly with the increase of filling rate.The filling rate is an important factor to control the strata movement and surface deformation, the results of the study are of great significance to guide practice in filling mining