Analysis On Vibration Of High-Speed Railway Viaducts And Field Vibration Isolation

When a high-speed train drives through the viaduct system, the vibration of the viaduct will be induced due to the moving loads. The vibration, which propagates to the ground through the foundation of viaduct, may be harmful to the environment. Recently, people have been paid a good deal of attention to the affects of vibration induced by high-speed trains on environment.In this thesis, a typical high-speed viaduct is taken as the object of study and the Finite Element Method is employed to analyze the vibration induced by trains and the field vibration isolation.The vibration of a train-bridge-ground system is a typical dynamic soil-structure interaction problem. Such problem can be treated by the sub-structure method. The train and the bridge are taken as the upper sub-structure, and the ground and the installation for isolating vibration as the other sub-structure. This establishes two models for these two sub-structures to perform the analyses respectively. The main research contents include:(1) The train-bridge system's analytical methods are researched, and the vibration analysis that the moving train load put on the train-bridge system are discussed. The counteractive pier force is obtained by calculating a simplified model.(2) The generation of the vibration and the spreading rule are introduced. Showing the fundamental principle of the barrier isolation, it will get good barrier effective when choose the reasonable position and size.(3) The plane strain model of FEM is established to analyze the honeycomb WIB system. The isolation effects of the honeycomb WIB with two rows are investigated when the packing material are set as soil-pile wall, cored-pile wall and tyre-pile wall and the distance from the source location is twenty meters, thirty eight meters and some valuable conclusions have been drawn.(4) 3-D FEM model including the embankment, the barrier and the building is built to analyze the effects of the different filling materials. These works are of theoretic and engineering values and present theoretic basis to engineering designs.