Seismic Response Analysis For Long-span Continuous Rigid Frame Bridges With Consideration Of Pier-soil Coupling Effect

With the rapid developments of economic construction in the recent years in China, the large-scale bridge constructions in China have also a rapid development. New structural types in the bridge constructions have continuously appeared. How to ensure the safety and reliability of bridge structures" under the possible earthquake excitation? How to furthest avoid the loss of life and personal injury? How to reduce the economic losses and casualties? In the meantime, the designs of the bridge structures are not too conservative. These problems attract more and more attentions in the bridge engineering field. The anti-seismic researches now face many new topics. Currently, the design approaches have been developed and changed. The old bridges designed by the old approaches have the risk to some extent under the earthquake. Therefore, a large-span continuous rigid-frame bridge is taken as an engineering example in this work. The anti-seismic property is investigated that includes the following aspects.(1) The anti-seismic design theories for the large-span bridges are reviewed. The current situation and the existing problems of the anti-seismic design theories are addressed.(2) The basic theories of the earthquake response analyses are introduced. The finite element analytical model for a real bridge has been established. The dynamic property of this bridge is analyzed. The natural frequencies and the vibration modes are calculated. In addition, the pier-soil coupling effect has been considered in the dynamic calculations.(3) Based on the structural dynamic property, the seismic responses are calculated under the 2-D and 3-D seismic inputs by using the response spectrum approach. Moreover, the dynamic responses under the vertical seismic input are also calculated. In addition, the time history analysis is performed under the uniform excitation. Different seismic waves are compared. Then, a modified seismic wave input is employed to calculate the time history response. The results are compared to the ones by the response spectrum approach.In the end of this thesis, the results are concluded. Some conclusions and suggestions are proposed. Some problems are pointed out in the future work.