Seismic Responses Of High-speed Railway Bridge System Subjected To Near Foult Ground Motions

Near-field earthquake has a serious impact on civil engineering structures, which has attracted wide attention, but there is not specialized design and evaluation theory system on near-fault pulse-like ground motions in China, the near-fault effect have seldom been considered in existing research. In recent years, the high-speed railway develops rapidly in China, the dynamic performance of high-speed railway bridge structures and seismic safety under near-field earthquake have become anissue that must be considered. Therefore, this project will deeply analysis and discuss the seismic response of high-speed railway-ballastless track-bridge system under near-field earthquake.ANSYS software is used to establish the whole high-speed railway-ballastless track-bridge system under the earthquake, with the ballastless track structure embedded in the high speed railway-bridge system, analyze the elastic seismic responses of the high-speed railway-ballastless track-bridge system. The influence of the different parameter such as different earthquake ware, earthquake strength and pier height is studied in the paper.The research covers the following aspects, based on the records from PEER NGA, the near/far-field earthquake database is established, the fine model of high-speed vehicle-ballastless track-bridge-pile-soil system is built up subjected to horizontal and verticlal ground motions. The seismic response of the high-speed railway-ballastless track-bridge system during earthquake are calculated, the effects of pulse-like ground motions and vertical earthquake on the system are analyzed.The calculation results show that, the largest deformation demands of bridge structure under long-duration high-amplitude pulses in near-fault records will be observed. The seismic response of high-speed railway-ballastless track-bridge system will increase with the increase of the pier height and earthquake. The effect of seismic action on the dynamic response of the system is greater than the effect of the dynamic response of the train speed to the system.