Seismic Response Analysis Of The Wulongjiang River Large Bridge In Fu-Xia Line

With the continuous constructions of long-span bridges in recent years, the seismic responses of these bridges have become an increasingly serious problem researchers and engineers are concerned about. As a lifeline project, Bridge will bring about great losses to people's lives and property once it is damaged in an earthquake. However, at present, most of the seismic design criterias for bridge engineering both at home and abroad are only applicable to common bridges with moderate span, and for long-span bridges exceeding the applicable scope, no existing criterion can be followed in seismic design. Secondary, the seismic responses of long-span bridges are very complicated because many effects should be considered such as muti-point excitation, traveling effect, various nonlinearities, pile-soil interaction, etc. Furthermore, software which are needed in seismic analysis for long-span bridges have more or less shortcomings. Therefore, it bears great practical significance to carry out seismic response analysis of long-span bridges.With the background of Fu-Xia line Wulongjiang River large bridge, the thesis, based on brief introduction of the basic theory on seismic response analysis, sets out to make detailed seismic response analysis on the large-span high-speed railway bridge by using ANSYS software.The paper presents the following:(1) Spatial FE models for three schemes of the bridge are established. Based on these models, model analysis is carried out by use of the subspace mode extraction method. The effect of pile-soil interaction on bridge dynamic characteristic is discussed in the process.(2) Elaborating on the theoretic basis of response spectrum method as well as the problems concerning its realization in ANSYS. By using the function of ANSYS spectrum anlysis, response spectrum analysis of the three themes under 3-D seismic input circumstance is carried out while performing comparison and analysis of structural response value under different input circumstance.(3) Elaborating on the basic theory of time-history analysis as well as the problems concerning its realization in ANSYS. Based on the function of transient dynamic analysis and Newmark-βmethod in ANSYS, the time-history analysis of the continuous beam scheme actually choosed for the bridge is carried out while performing comparison and analysis of internal forces and displacement response of various key sections under various seismic input circumstance.Via detailed calculation and comparison & analysis of the bridge,conclusions and suggestions, which are useful for carrying out seismic designfor the long-span high-speed railway continuous beam bridge, are gained hereby.