Stability Assessment of Bolt-Reinforced Rock Slopes Considering Corrosion Effects

In practice, bolts are commonly used to stabilize rock slopes. It is well recognized that anchor bolts may experience corrosion during their service life, thus leading to a reduction in anchoring effectiveness. However, prior research rarely accounted for the reinforcement loss caused by bolt corrosion, potentially resulting in an overestimation of slope safety. To address this gap, this study proposes a novel kinematic limit analysis framework for evaluating the stability of bolt-reinforced rock slopes while explicitly considering bolt corrosion. The generalized Hoek–Brown failure criterion is employed to represent the nonlinear strength behavior of rock masses and is linearized using the generalized tangent technique. A time-dependent empirical corrosion model is integrated to describe the progressive reduction in bolt strength, including both bond deterioration and tensile degradation. By combining the work–energy balance principle with the shear strength reduction method, an implicit expression for the safety factor is derived. Parametric studies reveal that, considering bolt corrosion, the safety factor of bolt-reinforced rock slopes decreases significantly over time, and some initially stable slopes may become unstable. This implies that corrosion effects should be incorporated into the stability analysis and design of bolt-reinforced rock slopes. A water–cement ratio above 0.50 greatly increases corrosion depth and accelerates the decline in safety. Maintaining a ratio below 0.5 and increasing the protective layer thickness can reduce the corrosion effect and improve stability. Early-stage stability is mainly governed by bond strength, while later-stage stability is controlled by the tensile strength of bolts. Although increasing bolt length and reducing anchoring angle improve initial stability, they also accelerate long-term degradation. The findings of this study can provide insights into the stability analysis and design of bolt-reinforced rock slopes.