Dynamic simulation and failure analysis of intermittently jointed rock cells and slopes based on a novel spring-based smoothed particle hydrodynamics method

A spring-based smoothed particle hydrodynamics (SB-SPH) method was developed to reproduce the progressive failure process and quantify the factor of safety (FOS) of a slope within the intermittently jointed rock mass. In the improved framework, the equations of contact forces between particles are introduced into the Eulerian formulations of SPH, and a unified governing equation for coupled cracking and contact is developed. Moreover, the initial discontinuous domain searching algorithm has been proposed to realize the generation of prefabricated discontinuities. A sliding benchmark test of rectangular blocks on inclines is conducted to verify the validity of the contact behaviour. Jointed rock cells under uniaxial compression with varying dip angles are employed to validate the accuracy and reliability of SB-SPH in cracking and contact behaviour. Additionally, the effects of intermittent joints on the progressive failure process and FOS of slopes characterized by various dip angles and rock bridge lengths are revealed. In comparison to horizontal joints, the FOS of the slope increases by 49.18%, 88.52%, 122.95%, and 173.77% when the joint dip angles are 30°, 45°, 60°, and 90°, respectively. Compared with the situation with persistent bedding planes, when the lengths of the rock bridges are 1 m, 2 m, and 3 m, the FOS of the slope increases by 19.74%, 51.32%, and 78.95%, respectively. The results indicate that as a continuum-discrete method, SB-SPH precisely reproduces the process of crack initiation, propagation, and block contact behaviour, such as frictional sliding at multiple scales.