Numerical Simulation for Permeability Evolution Process of Excavation Roadway Surrounding Rock Mass

Coal-rock mass permeability is sensitive to the stability of coal and rock and gas coupling system, it has some engineering significance to study permeability evolution simulation of the tunneling lane surrounding rock, which could reduce accident rate of coal and gas outburst. We established permeability and porosity model according to linear porous elastic medium basic law, and established gassy coal heat-flow-solid coupling dynamic equation based on rock mass mechanics, percolation theory, heat transfer theory and heat-flow-solid coupling theory. Combined with Comsol Multiphics and MATLAB, we simulated the model, and achieved the evolution process of tunneling lane surrounding coal and rock permeability, and discovered that variation of stresses is central to interpreting coal permeability. The permeability is different between permeability evolution and flow-solid coupling model, because of temperature affect.