On the Relationship Between Normal Stiffness and Permeability of Rock Fractures

Abstract

Abstract The hydraulic permeability and normal stiffness of rock fractures are fundamentally related, which can serve as a probe for assessing hydro‐mechanical properties in a variety of geo‐engineering contexts. We present experimentally validated numerical simulations of fracture closure and fluid flow processes in realistic aperture structures with mean in the range of 0.01–2 mm. A relatively simple relationship between permeability and normal stiffness is derived in the effective medium regime, using the elastic modulus of the rock matrix, the mean mechanical aperture, and the relative standard deviation (RSD) of the local mechanical aperture. The established relationship between stiffness and permeability appears independent of scale or orientation.