Abstract:Taking the downward approach paste filling roof of Wushan Copper Mine as the research object, the stability analysis of the roof filling body is carried out. The strength parameters of the rock mechanics test of Wushan Copper Mine ore body and filling body are analyzed, and it is concluded that the strength of the paste filling roof mainly depends on the strength of the bottom layer with a 1: 4 lime-sand ratio. On the basis of considering a reasonable safety factor, the elastic mechanics method—simply supported beam model and thin plate model are used to theoretically calculate the uniaxial compressive strength requirements of the bottom filling body under the working conditions of different mining section sizes. After calculation, the actual uniaxial compressive strength and uniaxial tensile strength of the filling body meet the stability requirements of the access roof. Combined with FLAC3D numerical simulation software to analyze the stability of the bottom layer, according to the analysis results, there are tensile and shear plastic zones in the roof bottom layer, but the overall range is small, and there is no penetration between the two, and the roof is generally in a stable state.