Abstract: The repetitive shear test and anisotropic shear test of structural planes with the same morphology have always been challenging in the experimental study of shear mechanical properties of rock mass which are of significance to the mechanical response during excavation and stability analysis, evaluation and control of engineering rock masses. The key to this challenge is to reproduce the structural plane topography for the same type of rock. Based on 3D scanning and 3D carving techniques, a large number of marble structural plane samples with three different roughness are reproduced. To investigate the anisotropy of shear characteristics, direct shear tests are conducted on marble joint samples with same surface morphology under different normal stress conditions. The results show that under the same normal stress but different shear directions, the shear strengths, dilation characteristics and shear failure characteristics of marble joint samples with the same surface morphology are obvious anisotropic. The anisotropy of shear strength is largely dependent on the anisotropy of joint roughness. With increasing normal stress, the anisotropy of shear mechanical characteristics of rock joint gradually decreases. The 3D carving technique is a good method to investigate the anisotropy of shear characteristics of natural rock joints and can play an important role in further study of this problem.

Key words: rock joint morphology, 3D carving, roughness, 3D scanning, anisotropy