Abstract: In view of the surface subsidence caused by goaf unstability, the macroscopic mechanical parameters of the rock mass of a mine is determined.Through FLAC3D  numerical simulation study,the surface deformation scope is delineated and corresponding safety monitoring work is done.Based on the above study results,the disposal measures of goaf and surface subsidence area is proposed by using unclassified tailings cement filling method.The study results show that the surface subsidence problem,the safety hazard problems existed in goaf by the applications of the above disposal measures,besides that,it is also help for solving the safety environmental problems caused by tailings emission,and the goal of green mining can be realized.

Key words: Goaf, Surface subsidence, Numerical simulation, Tailings filling