High-speed Railway Bridge Take Into Account The Pile-soil Interaction Dynamic Response Analysis

With the construction of high-speed railway, the study on high-speed railway bridge has important significance. For high-speed railway bridges, in addition to the superstructure and the bridge bearings, the pier-pile system can change the dynamic characteristics of the railway bridge. As the high-speed railway construction in China is the first time, many proposed high-speed railway bridges that across the soft soil area of the country, need to solve dynamic response under high-speed train loads. Thereby, It is urgent to analyze the dynamic performance of bridge under the high-speed train considering the affect of "the bridge-Pile-Soft System" in civil engineering of China, and it is very important for the development of high-speed railway bridge. Meanwhile, Our country is a seismic country where earthquake frequently happens and where seismic area is widely distributed. Therefore, the study on dynamic characteristics of the high-speed railway bridge is the conduct research.1,The paper introduces the vehicle-bridge coupled vibration and vehicle-bridge coupled vibration under earthquake at home and abroad. In order to consider the influence of pile-soil interaction, spatial pile-soil model is established according to the finite element method, and the influences of infinite soil on the structure is simulated using three-dimensional viscous boundary.2,Based on bridge structural dynamics, vehicle dynamics principles, it also establish train-bridge model with and without earthquake and train-bridge vibration equation under earthquake.3,According to the typical characteristics of deep soft soil site, Shanghai is selected as the typical site, and the Beijing-Shanghai high speed railway with the 32 m box girder bridge is selected as the calculation model. The realistic finite element model is establithed, and the responses of bridge is analysised, the calculated results reveal that considering the pile-soil interaction will reduce the frequency of the vibration mode. Based on this model, the dynamic responses of the bridge in the soft soil site with and without seismic loads are analyzed, some meaningful conclusions are presented. 4,The laws of seismic responses of high-speed railway bridge are analyzed under different train speed, seismic wave intensity and pier height, and reasonable calculated depth of Shanghai typical soil layer is determined.