Dynamic Response And Running Safety Analysis Of Train-bridge System Subjected To Wave Loads

In recent years, more and more cross-river and cross-sea bridges are constructed, which are often subjected to the dynamic actions of strong waves. The waves acting on the bridge piers can influence the dynamic responses of the train-bridge system, and even the safety of passing trains. The Jiujiang Yantzer River Bridge is used as an example to study the dynamic response and safety of the train-bridge system under dual actions of trains and wave forces. The work done in this thesis is as follows:(1) The research developments of wave theories and random process theories are reviewed. The research achievements on the wave-excited bridge responses and the safety of passing vehicles are summarized.(2) Two wave simulation methods, the linear superposition method and the linear filtering method, are introduced. Based on the P-M spectrum, the random wave is simulated. Some factors that affect the quality of spectral estimation are discussed, including wave number, time length, sampling points. The results show that the simulated spectra approach the object more and more with the increase of wave number, time length and sampling points.(3) The Morison equation and the dynamic response computation method for piers are elaborated. The dynamic responses of a real bridge pier are computed based on the proposed method.(4) The analysis model of train-bridge interaction system subjected to wave loads is established on the basis of the vehicle dynamics, bridges dynamics, and fluid dynamics. The corresponding computation program is worked out.(5) Using the Jiujiang Yangtze River Bridge as a case, the dynamic responses and passing safety of trains are analyzed with the established theory and computation program. The influence laws of the train speeds, water depths and pier stiffness on the dynamic responses of the bridge are summarized. In the end, a conclusion is drawn that the lower the pier stiffness, the greater the influence of wave loads on the bridge responses and passing safety indices...