Based on the physical, mechanical and hydromechanical properties of the fractured rock, it simply introduced the statistics method, JRC method and fractal method and others for describing the fractured rock surface. Though comparing these methods above, the Duo-dimensionless parameters method (i.e. the dimensionless asperity angle and the dimensionless asperity area) has been proposed. And the physical and mechanical meanings of the two parameters have been analyzed, those two can combine the geometry characteristic, the mechanical and hydromechanical properties, also can better describe the surface topography of the fractured rock. And more, the seepage property of the fractured rock under different stress conditions has been presented using the Duo-dimensionless parameters, which can provide a foundation for research the relations between surface topography and the mechanical and flow properties of fractured rock.
Fractured media widely exit in the nature world. Such as the rock mass, it is about two thirds of the land surface. And there are a lot of engineering would be carried out in the rock mass. For example, the dam foundation, underground cave, oil and gas engineering, high level radioactive waste disposal and so on. Obviously, the physical and mechanical properties of the fractured media have a closely connection with the topography of the surface. Then the description of the surface is much more important and fundamental.
The rock mass quality and rock stability and the hydromechanical properties are subject to the width and the roughness of the rock joint. (Witherpoon et al. 1980) and Taihua Yang et al. found that the flow quantity has a cubic law with the fracture width, and has a direct ratio with the roughness of the joint. The deformation and the shear strength of the joint are subject to the joint roughness under the medium normal stress (Byelee 1978). With the different roughness, the failure mechanism of the rock joint has changed (Patton 1966). And the rock shear failure mechanism proposed by Barton reflects the influence of the joint roughness coefficient (JRC) (Barton 1977). Recently, the relationship between JRC and the fractal dimension D are studied by many researchers (Lee 1990). Xie. H obtained that the fractal dimension and the intercept are two key parameters of the rock surface (Xie 1993).