2. Theoretical model
The fiction behavior of geomaterials is considered to be the random and
continuous contact of microscopic asperities, resulting in the
accumulation of contact deformation and friction, which eventually
develops into the sliding of the rough contact surface. Therefore, the
theoretical part includes the characterization of the random contact
process of the contact surface, the deformation mode of the contacting
asperities, and the friction-slip behavior of the rough contact surface.