Numerical Simulation for Roof and Surface Subsidence Process Caused by Paste Filling

The moving rules of overburden rock and surface subsidence induced by paste filling mining are studieded and compared with caving method.Paste filling mining will become very important in the near future coal mining.Therefore,the numerical simulation is made with the program FLAC based on the object of mining under village in a certain coal mine.The detailed mining and filling process is simulated in which the filling intensity keeps increasing.The dynamic subsidence curves and control effect of roof and surface are presented,obtaining the rules of roof and surface subsidence as compared to caving method.The results show that the maximum subsidence coefficient is 0.11 and the paste filling mining can effectively control the strata movement,having a good effect on reducing the subsidence.The amount of subsidence in the early period of filling has a large percentage of the total subsidence.Decreasing the roof divulging time and paste curdling time and increasing roof supporting intensity and improving the quality of filling are the key to control the subsidence.