ABSTRACT
Since the 21st century, the focus of China’s transportation infrastructure has gradually shifted to the mountainous and karst areas in the central and western regions. The construction of tunnels and underground engineering is faced with severe tests of complex structure, changeable geological environment and frequent disasters. For this reason, this paper mainly conducts seepage research on fractured rock masses by constructing a dual-media seepage model. It is assumed that the fault fracture zone is a continuous medium composed of a pore system and a fracture system. The two systems overlap and are evenly distributed throughout the media system. The fractured rock mass is considered to be composed of two media: fractured media for water conduction and porous rock media for water storage. The seepage model of fractured media and the seepage model of porous media were established for the two media, respectively. The pores and pore rock mass alternate formulas are used to connect to form a coupled equation to solve. At the same time, for the dual-medium seepage model, two Richards equations combined with water exchange function are used to form coupled partial differential equations to express saturated and unsaturated seepage. Finally, the calculation formula of the total permeability coefficient K of the fault fracture zone is obtained.
