Combined Effects of Wind and Snow on High-Speed Train–Bridge Coupled System

During the winter months, the challenging natural environment characterized by strong winds, ice, and snow can greatly affect the functioning of high-speed railways. This paper focuses on the combined effects of wind–snow flow on the safety of the high-speed train–bridge coupled system. The research takes the 5 × 32m simply supported beam of the Harbin–Dalian high-speed railway as a case study to examine the dynamic response and safety indices of the coupled system. A CFD–DEM wind–snow flow coupling model is developed based on the Euler–Lagrange method, and the study compares the aerodynamic characteristics and dynamic responses of the vehicle–bridge system under the influence of crosswind versus the combined effects of wind–snow flow. The analysis also includes an examination of the vehicle’s dynamic response at different wind and train speeds. The results suggest that the wind–snow flow condition significantly alters the aerodynamic coefficients compared to the crosswind condition, with a reduction in drag but an increase in lift and moment coefficients for both the bridge and the train, indicating a more intense dynamic response in the presence of wind and snow.