The state of tensile-shear stress can easily lead to rock mass damage and even instability. To investigate the tensile-shear failure law of jointed rock mass

numerical simulation of rock mass containing coplanar intermittent cracks under tensile-shear test is carried out through FLAC3D simulation software. For getting high fidelity actual conditions

Mohr-Coulomb constitutive model and maximum tensile stress criterion are amended with rock statistical damage and a function is applied to make the initial mechanical parameters obey the Weibull distribution. Then

failure modes and laws of rock mass are studied under tensile-shear loading. And the influence of homogeneous degree

normal tensile stress and shear rate on rock mass failure modes and processes

as well as its mechanical properties were discussed. The main conclusions can be drawn as follows: (1) Due to the heterogeneous characteristics of natural rock mass

the failure mode is dominated by tensile failure

with little tensile-shear mixed failure. Meanwhile

the initial rupture zones are scattered and then form a strip-shaped fracture surface. The macroscopic mechanical properties of heterogeneous rock mass are obviously weakened than homogeneous rock mass without damage evolution. (2) Heterogeneity has a significant impact on the failure process and strength of jointed rock mass. That is

with the increase of homogeneous degree

the failure mode changes from diffuse type to the concentrated

and the rupture surface roughness increases. The macroscopic strength of jointed rock mass enhances

but there is a ceiling which represents strength of the homogeneous. (3) Under the low stress level

the increase of tensile stress does not change the main rupture mode of rock mass which is tensile failure. However

the proportion of shear and mixed failure are obviously less. Meanwhile

the shear strength of rock mass decreases and the roughness of fracture surface increases. (4) The shear rate has a significant effect on the mechanical properties of rock mass. In the static loading range

the shear strength of rock mass increases with the growth of shearing rate

and the magnitude of the increase is getting smaller.