Numerical characterization of slope rock mass through considerations of hydraulic and mechanical properties

In this paper, the slope rock mass is numerically characterized by considering hydraulic and mechanical properties using two distinct element models. The flow rate and permeability are calculated from localized fluxes through rock masses with varied fracture orientations and scales. Flow models suggest that rock mass permeability is predominantly controlled by fracture size. High rock mass permeability is simulated when the fractures are enlarged. Hydraulic anisotropy is captured when the difference in the fracture size is amplified. The mechanical properties of the slope rock mass are characterized through numerical shearing tests. In general, high permeability corresponds to low shearing resistance of the rock mass. The fractures obliquely distributed to shearing direction lead to additional shearing resistance. Enlarged fractures reflect high conductivity of the rock mass structure and decrease the shearing resistance. Mechanical anisotropy of the rock mass is also captured and attributed to the difference in the fracture size. The relations between hydraulic and mechanical properties are examined, and negative exponential relations are fitted between rock mass cohesion and permeability. The research introduces permeability as reference to slope rock mass characterization and provides reliable methods to this challenging issue.