Numerical study on seepage properties of rock mass with non-penetrating fracture using discrete element method

This paper aims to investigate the seepage process of fractured rock mass at a mesoscopic level, using the discrete element method. To this end, an improved pipe flow algorithm is proposed within the framework of particle flow code, including the heterogeneity of initial micro-cracks and the deformation of solid skeleton. A series of numerical samples with a single non-penetrating fracture are then studied. The relationships between the rock permeability and different properties of fracture (i.e., the aperture, dip angle and length) are investigated. The influence of fracture properties on the distribution of pore pressure in the rock mass is also analyzed. The obtained numerical results exhibit that the seepage properties of rock mass with non-penetrating fracture depend strongly on the dip angle and length of fracture and are slightly disturbed by the fracture aperture. Moreover, its permeability is almost of the same order as that of non-fractured rock. The numerical results and mesoscale analysis can help us understand the influence of fracture properties on the permeability of host rock and provide practical guidance for the prevention of hydraulic disasters and the development of mineral resources.