Abstract: A simple and rapid method of triaxial test on non-filled rock specimens containing irregular discontinuities by using rock mechanics test system (MTS) is presented in this paper. Multiple shear strength data can be obtained by using this method in the presence of only one single specimen. The difficulty of preparing test specimen is overcome and the highly discrete test results can be avoided. In addition, approaches to determine the parameters of linear Mohr-Coulomb criterion fitting, power function fitting and nonlinear Barton equation fitting according to test results are examined and the results of different approaches are compared to verify the rationality of the method. The application scope of the test method is also put forward. Results suggest that power function fitting and nonlinear Barton equation fitting are superior to Mohr-Coulomb criterion in reflecting the nonlinearity of shear strength of jointed rock. When 0.01<σ_nj/JCS<0.3, the result of shear strength of jointed rock obtained by the two fitting methods are reliable; when σ_nj/JCS>0.3, the result is larger.

Key words: non-filled rock, discontinuity, shear strength, triaxial test, determining method