A Numerical study on the correlation between fracture transmissivity, hydraulic aperture and transport aperture

Sawada, Atsushi ; Takebe, Atsuji*; Sakamoto, Kazuhiko*

Quantitative evaluation of the groundwater velocity in the fractures is a key part of contaminants transport assessment especially in the radioactive waste disposal programs. In a hydrogeological model such as the discrete fracture network model, transport aperture of water conducting fracture is one of the important parameter for evaluating groundwater velocity. To study relationship between transport aperture, hydraulic aperture and transmissivity, numerical simulations were conducted by using a single fracture model with a heterogeneous aperture distribution. The results show that the mean geometrical aperture is the most sensitive parameter among the three variable parameters in this study. It is also found that the contact area ratio affects transmissivity more than the JRC, Joint Roughness Coefficient, and while the JRC strongly affects the velocity and transport aperture.