AN INVESTIGATION OF THE MECHANICS OF ROCK JOINTS .2. ANALYTICAL INVESTIGATION

In this paper, which is the second of a two-part series, an analytical investigation of the mechanical behavior of initially closely mated joints in rock undergoing small sliding displacements is undertaken. Guided by the experimental observations reported in Part I, the goal is to develop a quantitative theory for joint behavior, including phenomena such as dilatancy, damage of surface roughness, and cyclic sliding behavior. The approach is by microstructural modeling in which a reasonable surface idealization is employed along with physically acceptable models for various aspects of joint behavior such as elastic joint deformability, sliding criteria and damage evolution. The result is a macroscopic constitutive law for joint behavior which is essentially nonempirical, is easy to evaluate, valid for general small displacement sliding histories, and is easy to implement in analysis software.