Study on steep slope stability of coal mine under open-pit and underground mining

Northwest slope of An Taibao open-pit mine in Shanxi province is under the condition of open-pit and underground combined mining, based on this slope project, the computation model is established for research and analysis using MIDAS / GTS and FLAC3D software, the deformation response characteristics of steep slope are researched by the method of numerical simulation. It is demonstrated that the steep slope formed by open-pit mining has a certain deformation response after the underground mining of No.4 coal, which is little effected, with the continuing advance of No.9 coal mining working face, the deformation of steep slope is increasing, it is expected that the maximum subsidence will be up to 3.12m, and the maximum displacement toward free face will be up to 0.48m after the mining of 9005 working face. According to the above study, it is suggested that monitoring and reinforcement measures should be taken in the study area, in order to realize sustainable development and utilization of coal resources.