Abstract: The jointed rock mass is a discontinuous body with special structure, and shows the anisotropic mechanical characteristic. In order to understand its complex mechanical characteristic, the mechanical effects of single joint surface is analyzed theoretically; and the triaxial compression test is conducted on samples with single prefabricated joint. The test results show that the mechanical characteristic of jointed samples is governed by either joint surface or rock. Compared with the intact samples, the mechanical parameters of jointed samples reduce inordinately. The Young’s modulus, compressive strength, cohesion are in U-shaped along with joint inclination and the minimum value occured at the inclination of 60° jointed samples. On the contrary, the internal friction angle increases linearly with the joint inclination. With the increasing of confining pressure, the ratio of maximum to minimum of Young’s modulus and compressive strength decrease; it shows that differences of mechanical characteristic of various inclination jointed samples lessen.

Key words: jointed rock masses, prefabricated joint sample, conventional triaxial compression test, anisotropy, mechanical characteristic