Study on the influence of filling roadway width on overburden migration in continuous mining and filling mining

In order to solve the problems of surface subsidence, resource waste and environmental pollution encountered in the traditional mining process, based on the background of Baodian Coal mine, the influence of filling lane width on overburden migration was analyzed through theoretical research and numerical simulation. Through mechanical model calculation, the nonlinear relationship between the width of the filling lane and the safety factor of the column is revealed, and the reasonable width of the filling lane in ShanDong Coal mine is determined to be 7 meters. FLAC ^3D software was used to simulate the overburden migration in different filling stages of the filling roadway with 7m width. The results showed that: In the first stage, the boundary coal and the coal protecting roadway mainly bear vertical stress, with the maximum bearing pressure of 16.1 MPa, while the filling body hardly bears any load, and the roof subsidence was wavy in the X-axis direction of the model. In the second stage, the overlying rock pressure is mainly borne by the boundary coal body, with the maximum bearing pressure reaching 19.9MPa, and the filling body bearing pressure presents a wavy distribution. The maximum deformation of the roof in the second stage is 269 mm, which meets the safety requirements.