Numerical Simulation of Crack Propagation in Jointed Rock Mass Based on an Enhanced SPH Method

The enhanced Smoothed Particle Hydrodynamics (SPH) method is proposed for simulating crack propagation in the jointed rock mass. The kernel function of SPH is improved, and a novel governing equation for intact and damaged SPH particles has been proposed. The SPH method is applied to conduct compression tests on jointed rock specimens under varying joint inclination angles and heterogeneous coefficients. Furthermore, the SPH method is employed to analyze multiple jointed rock tunnels considering different inclination angles and lateral pressure coefficients. The results demonstrate that the improved SPH method effectively reproduces crack initiation, propagation, coalescence, and large deformation of jointed rock masses without the need for mesh refinements. The parameters used in the method have macroscopic physical meanings, reducing the calibration time for parameter selection. Additionally, SPH offers higher computational efficiency in particle search compared to the Discrete Element Method (DEM) due to its continuous integral interpolations. For jointed rock cells, the highest strength is observed at a joint inclination angle of 90°, while the lowest strength is found within the range of 0° to 30°. Lower heterogeneous coefficients result in more widely distributed tensile cracks and lower uniaxial strength. In multiple jointed rock tunnels, the rock mass parallel to the joints is more susceptible to tensile failure, and increasing the lateral pressure coefficient intensifies crack propagation and damage (failure development). The improved SPH method provides a well-defined cracking strategy for modeling crack propagation in jointed rock masses of different scales.