Rough cross joints widely exist in actual rock mass. The laboratory study on the mechanical fracture evolution of specimens with rough cross joints at different angles can provide important guidance for rock mass engineering. Based on Barton joint profile

we use 3D printing to generate rough cross joint models with different angles. Then we carry out uniaxial compressive tests after pouring the specimens. The deformation characteristics of the surface are processed and analyzed by the digital image correlation (DIC) technology. The results show that the uniaxial strength of specimens with larger dips of primary joint is less than that of specimens with smaller dips. The influence on the uniaxial compressive strength and elastic modulus of the specimen is most significant when the angle γ between the primary and secondary joints is between 45° and 60°. We analyze the obtained strain contour figures by DIC

as well as the whole range of strain of joint tips and strain rate surge points. The observations are listed as follows. The fracture initiation mainly occurs at the upper and lower ends of primary joint and the upper end of secondary joint

and the initiation stress is between 90% of the peak stress and the peak. The fracture propagation rate is slow in the yield stage

and the rapid expansion mainly occurs in the post-peak stage. The fracture initiation direction of the rough cross joint specimen is different from that of the smooth joint specimen. The fracture at the tips of joints is mostly in the form of shear

and evolves into tensile fracture under the action of maximum principal stress. The stress intensity factor at the lower end of the primary joint is larger than that at the upper end of the secondary joint

which indicates that the primary joint plays the main role in the fracture of the specimen. KII at the joint tipis is greater than KI

which indicates that the shear effect is greater than the tensile effect on the initiation and propagation of fracture.