Hydraulic Characterization of Fractures for DFN Modeling of Dam Foundation Rock Mass

Abstract One of the important requirements of foundation rock mass under dam is resistance to leakage of water. The mechanism of water leakage depends on the hydraulic properties of rock mass. When considering water leakage in fracture-dominant rock mass, the pathway of the flow is controlled by distributions and connectivity of permeable fractures. In such case, a use of discrete fracture network (DFN) models is effective to simulate the groundwater flow, as DFN approach can express fractures stochastically in three-dimension based on statistical distribution of fracture parameters. One of the key challenges when building a DFN model for dam foundation rock mass is hydraulic characterization of fractures. Hydraulic characterization in this context refers to the process of assigning hydraulic properties to the fractures generated from the geometric information. In this paper, an approach to construct a DFN model for dam foundation rock mass is proposed, with a focus on hydraulic characterization of fractures, along with a case study of foundation rock mass of an embankment dam in Japan to demonstrate the application of proposed approach.