Research on deformation and failure characteristics of floor of working face on high pressure aquifer

Water pressure is one of the important factors affecting the deformation and failure of the floor. In order to explore the characteristics of the deformation and failure of the floor during the advance of the working face in the high pressure aquifer, the working face of Xingtai Mining Area is taken as the engineering background based on the flow between the seepage and deformation of the porous medium. Based on the solid coupling theory, according to the hydrogeological conditions of the project site, the multi-physics simulation software COMSOL Multiphysics is used to establish a finite element numerical model and the in-situ measurement is carried out through the water pressure test. The stress distribution of surrounding rock and the characteristics of floor deformation and failure during the advancing process of the working face are analyzed, as well as the variation law of pore pressure at different failure depths of the floor. The research results show that as the increase of advancing distance of the working face, the bottom plate is prone to plastic failure, and the higher the pore pressure, the greater the plastic failure area and the failure depth.