A numerical investigation of compression and shearing effects on the hydraulic aperture tensor of rough fractures

Understanding the relationship between fracture characteristics and permeability is crucial in hydrogeology. While previous studies have investigated the significant factors for the permeability of fractures, they often overlook the tensorial nature of the hydraulic (apparent) aperture, potentially leading to inaccuracies in capturing anisotropic flow behaviors. Building upon existing research, we extend our investigation to explore the impact of shearing stresses on hydraulic aperture tensors of rough-walled fractures. Due to limitations in experimental designs, we employ numerical simulations at a local scale to assess the effects of shearing on hydraulic aperture tensors. We generate synthetic fracture walls using fractional Brownian motion (fBm) and conduct fluid flow simulations to upscale hydraulic aperture tensors under varying shearing and compressive states. Our findings highlight the importance of representing hydraulic apertures as tensors to effectively model anisotropic fluid flow in rough fractures and provide insights into the correlation between shear and hydraulic aperture.