关键词: &ldquo, 三下&rdquo, 开采, 地表稳定, 概率积分法, 安全开采深度, 数值模拟, 爆破振动

Abstract: In order to ensure the safety of surface villages，rivers and roads within subsidence basin and to maximize the exploitation of underground resources，and combing with the tailings cemented filling mining method under the structural condition of a large fault zone in a gold mine as a case，the safe mining depth of the mine is calculated as 108 m by using the theory of probability integral method，which is less than the thickness （130 m） of overburden rock and can meet the requirement of safety.The surface subsidence of a typical section within the movement range of "three-under" mining in a gold mine is studied and analyzed by FLAC3D numerical simulation method. Based on the calculation results it is show that the maximum inclined deformation is 0.022 mm/m and the maximum horizontal deformation is 0.019 mm/m.The deformation valus are close to the measured data，which meets the requirements of protection grade for buildings and structures. According to the characteristics of underground blasting engineering， the maximum allowable distance of blasting is calculated as 96 m，and the blasting vibration will not affect the surface. After the comprehensive analysis，it is concluded that the surface structures within the subsidence basin in the gold mine are safe and stable，which can provide reliable reference for the safety and efficiency production of the mine and the surface stability analysis of mining movement zone of similar mines.

Key words: “Three under&rdquo, mining, Surface stability, Probability integral method, Safe mining depth, Numerical simulation, Blasting vibration