A hierarchical model of rough rock joints based on micromechanics

A rough rock joint model is proposed in this study on the basis of micromechanics concepts. In the model, the global behavior of a rough joint depends on the microfeatures of the contact planes on the joint. The contact mechanics on contact planes controls the mechanical behavior of the joint via a homogenization process. Also, the complex mechanical behavior of a joint is associated with simple microfeatures of the joint, including the frictional properties and the structure of contact planes. To capture the feature of scale dependency of joint roughness, a hierarchical representation of a joint profile is proposed in the form of a multi-level-asperity model. Moreover, the constitutive relation of the multi-level-asperity model is derived through a recursive homogenization process. The proposed model's framework is general and systematic. Furthermore, major deformation mechanisms of joint asperities, i.e. interlocking, wearing, shearing-off, sliding, separation and degradation, are taken into account.