Assessing the residual stability of the cohesive-frictional slopes following high-speed railway loading

This study investigates the dynamic response of compound slopes under train-induced dynamic loading and evaluates their residual stability following train passage using three-dimensional finite element analysis. The train-induced loading was simulated using a moving load implemented through the movement function. The stability of the slope after the passage of the HSR dynamic load was evaluated based on the factor of safety ( FoS ) and failure mechanisms, which were determined using the strength reduction method (SRM) under non-associated flow rule conditions. Parametric analysis was conducted to examine the effect of cohesion ( c ), internal friction angle ( φ ), unit weight ( γ ), and slope angle ( α ) on slope performance. The results demonstrated that the slope angle strongly governed the wave propagation pattern, with steeper slopes producing a more concentrated dynamic response along the upper slope. Increasing cohesion and internal friction angle substantially enhances the factor of safety, while increasing slope angle and unit weight decreases stability. The failure mechanism analyses indicated that increasing the slope angle causes the deformation to become progressively localized within the upper slope, resulting in a transition from global to local failure. Conversely, increasing the soil shear strength promotes the mobilization of a larger soil mass prior to failure, leading to a transition from local to global failure pattern. The proposed numerical framework provides a reliable approach for assessing the residual stability of compound slopes following high-speed railway. The findings also provide useful information for researchers and practicing engineers involved in the analysis and design of high-speed railway infrastructure constructed on or adjacent to slopes.