Study on the moving deformation law of covered rock in paste backfill mining

To reveal the change pattern of the covered rock moving angle in paste backfill mining, FLAC^3D was used to simulate the moving deformation characteristics of covered rock under the influence of different factors of paste backfill mining in a mine, and the moving angle of covered rock at different horizontal heights was studied based on the simulation calculation results. The results show that the higher the filling body gray-sand ratio and the higher the filling rate are, the smaller the surface subsidence amount and the smaller the development height of the covered rock risk deformation area. There is an exponential relationship between the development height of the covered rock risk deformation zone and the cement-sand ratio of the filler, and the covered rock moving angle increases linearly with the height of the covered rock from the roof. Combined with the regression analysis, the relationship between the covered rock moving angle and the height of the covered rock from the roof and the cement-sand ratio of the filler was established, which further revealed the change pattern of the covered rock moving angle in paste backfill mining and provided a certain basic theoretical basis for the reasonable determination of the covered rock moving angle in mines.