Study On Correlation Between Surface Feature Of Structural Plane And Mechanical Property

Structural plane is an important part of rock mass, and it plays a key role in the process of deformation and damage. The property of a structural plane on mechanics is greatly affected by its degree of roughness, which is formed due to ups and downs of the surface of structural plane. On basis of mechanical behavior of joints surface, this paper demonstrates that it is reasonable to describe the degree of roughness by Joint Roughness Coefficient (JRC) in the model of JRC-JCS.Fractal geometry theory is used to describe the degree of roughness. There was a shortage in fractal description to the degree of roughness in the past, which was not able to fully reflect the whole situation of joints surface, because fractal calculation was only directed towards a curve on joints surface. To improve this situation, this paper uses a admeasuring apparatus which can measure three dimensional shape, and applies cubic covering method to calculate fractal dimension of fracture surface.Through shearing test, this paper analyzes the correlation between fractal dimension (D) and shearing deformation. At the base of the JRC-JCS model, this paper sets up an empirical relation between D and shear strength. From this method, we can obtain a shear strength which more approaches to true value compared with the method of Xie Heping.On basis of experimental analysis, fractal dimension reflecting the whole surface of joints can well quantitatively describe the degree of roughness. This paper offers a new approach for prediction of shear strength.