Study of Train Running Performance under Wave Load for Cross-Sea Bridge

The Pingtan Strait Bridge is in a complex and harsh marine environment. The wave loads could affect traffic safety and comfortability.Based on the numerical simulation for coupling vibration of the rail vehicle-bridge system,our software-BANSYS (bridge analysis system) was adopted for analysing the dynamic responses of vehicles and the bridge under extreme wave loads.To estimate the return periods of the wave load, velocities, water depths, stiffness of bridge foundations, and the responses of vehicles and the bridge were analysed.The results show that wave loads have a significant impact on the responses of the vehicle-bridge system; when the return period of the wave load is 50 years, the lateral displacement of the midspan exceeds the standard limit. The wave loads play a major role in the train running performance; with large wave loads, the dynamic response of the vehicle-bridge system is more sensitive to vehicle speed than with small wave loads. The scheme of low pile cap can effectively reduce the dynamic response of the bridge and vehicles under wave loads. The different frequently-used concrete strengths of the bridge foundations have little influence on traffic safety and comfortability, and the relative change in the maximum acceleration of vehicles is up to 3%.