Abstract:The axial compressive strength and deformation scale effect of five kinds of rock masses with fractal joints are studied by using the similar materials and the simulating block joints are prepared with vitriol paper. The experimental data of compressive strength and deformation changing with the joint fractal dimension for the same scale have been obtained,and two-dimensional empirical equations are developed based on the analyses of the experimental data. The experimental results indicate that the compressive strength and deformation modulus of rock masses decrease with the increase of scale and the joint fractal dimension;but the Poisson¢s ratio increases with the increase of scale and the joint fractal dimension. It can be generally concluded that the rock ductility increases with the increase of scale and the joint fractal dimension;and the damage process and form are controlled by the joint distribution dimension.