Numerical study on the failure evolution of rock slopes containing multi-flaws by strength-based fracture method

In this study, we adopt the proposed strength-based local maximum stress (SLMS) criterion to calculate the crack propagation of tensile and shear cracks in a plate with two parallel closed flaws at different rock bridge inclinations (beta) under compression. The effect of beta on the failure mode of rock bridges was investigated. Then, we modeled the three-section landslides caused by crack propagation under different friction coefficients to validate the effectiveness of SLMS in modeling crack propagation in slopes. Finally, the formation of sliding surfaces in four specific rock slopes with multi-flaws was modeled to investigate the effect of flaw distribution on the depth and shape of sliding surfaces of slopes. Results indicate that flaws located in the middle of the slope have a significant effect on the failure mode and the depth of the sliding surface at this location. Due to the small increments of displacement during the failure process of the slope, which are difficult to monitor, displacement monitoring methods are ineffective for landslide early warning. The instability of the rock slope is caused by the initiation, propagation, and coalescence of cracks, therefore, real-time monitoring of the micro-failure accumulation in the slope is beneficial for early warning of landslides. Moreover, the variation of contact status of crack surfaces during the formation of slope sliding surfaces was analyzed, and the effect of sliding surface formation on contact sliding distance and contact gap distance of crack surfaces was investigated.