Stability Analysis of Overlying Rock Mass of L Working Face Moving from Open-pit to Underground Mining and Slope Treatment Schemes

Taking the L working face of open-pit to underground mining in Wuhai Coal Mine as an example, based on the numerical simulation software FLAC^3D which made a detail analysis of deformation and mechanism of rock slope aimed at the two different mining schemes from inside to outside and outgoing, the results proved that when the mining sequence is from inside to outside, the slope moves to the underground mined-out area, which is good for slope stability; on the contrary, it would accelerate the failure speed, which is adverse to the slope stability. So underground mining should adopt the mining design of outward driving. At the same time, in order to ensure the safety of production and reduce landslide extent of the damage, we designed anchoring reinforcement method for load shedding based on the actual conditions.