The Vibration Environmental Evaluation Of Bridge Track Structure

With the development of economics, metro lines develop quickly in many big cities. At the meantime, the vibration and noise aroused by railway track were accused by people. In this thesis, the propagation of train-induced vibrations in the surrounding environment and their influence laws and the influence of related parameter to vibrations were analyzed on the basis of previous achievements of relevant researches. It can offer reference to feasibility research and environmental influence evaluate of bridge track vibration.At first, this paper described the cause of induced vibration of track structure and the indices of evaluating environment vibration. After it, introduce the research actuality of world on environmental influence and vibration reducing.On the basis of the theory of track structure and vibration, the model of ballasted track vibration is established under moving load by Ansys soft. It contains a 3D FEM of railway-bridge and a 2D dynamic plane stress model of soil and pier. Base on the model, analysis was done to get the natural frequency of the model; dynamic characteristic of soil-pier model was analyzed by comparing of finite analysis and theoretic calculation.In the end, dynamic characteristic of railway structure on bridge and vibration influence laws along the soil surface were analyzed under moving load, discussing the influence of train speed and structure parameter to vibration. Using 2D dynamic plane stress model this thesis studied vibration influence laws, discussing the influence of rail pad, ballast mat, pier support stiffness and vehicle speed on structural vibration. The results can offer reference to feasibility study, design and construction of viaduct railway track.