Shear behaviour of 3D nonpersistent jointed rock-like specimens: Experiment and numerical simulation

There are many nonpersistent joints in natural rock masses, and they play an important role in the mechanical and failure characteristics of rock masses. To investigate the shear failure behaviour of 3D nonpersistent jointed rock masses, laboratory tests and numerical simulations were conducted in this paper. The 3D nonpenetrating joints are created using a 3D printer, and five persistence ratios are considered. The experimental results show that the shear strength, cohesion and friction angle decrease with increasing joint persistence. A 3D DEM model containing 3D nonpersistent joints is established considering the joint persistence. The flat-joint model and smooth-joint model are used to model rock-like materials and prefabricated joints, respectively. The numerical results are consistent with the laboratory results in both shear strength parameters and failure characteristics. Combined with numerical results, the crack initiation, propagation and coalescence on 3D nonpersistent joint specimens were analysed at the microscale.