ABSTRACT
There have been a considerable number of studies on the influence of surface roughness. The shear strength along joints in rock is closely related to the surface roughness of the joints. Moreover, the values of the fractal dimension are directly proportional to surface roughness. It is seen that the fractal dimension may offer an unique approach to the quantitative description of surface roughness of rock joints. In this chapter, the authors will introduce the fractal studies of Brown & Scholz on the topography of natural rock surfaces. Unlike earlier descriptions of topography, the scaling of surface roughness is a fundamental part of the fractal model. They introduces their recent studies on joint profiles, in which the roughness of joint profiles is considered as a fractal structure with finite generations. The quantification of joint roughness has always been a problem in joint shear modelling. Generally speaking, fluid flow through a fracture (joint) is clearly a three-dimensional process of high geometrical complexity.
