Effect of shear-induced aperture evolution on fluid flow in rock fractures.

Understanding the shear-induced evolution of aperture size is critical for controlling fracture permeability in rock engineering projects. This study reports a robust procedure to evaluate the change of aperture size and its effect on fluid flow. A Finite Element Model is first calibrated based on the direct shear tests on a rough fracture to reproduce the uneven deformation of the fracture. A Fluent Computational Fluid Dynamics analysis is subsequently used to illuminate flow characteristics in the fracture without and with asperity deformation. The results indicate that the aperture size of the fracture increases dramatically with increasing shear displacement. However, the aperture size can be reduced slightly due to asperity deformation. Both the shear displacement and asperity deformation jointly influence flow characteristics in the sheared fracture (e.g., the development of eddy flow regions) and the accurate estimation of fracture permeability. [ABSTRACT FROM AUTHOR]