Anti-Seismic Performance Analysis For Long-Span Steel Truss Deck-Type Railway Arch Bridge

In recent years, earthquake disasters occurred frequently and caused immesurable loss. Under the effects of earthquake, bridges which are the most important traffic hub project are also destroyed. So, it is very theoretical and practical significance to do some anti-seismic research on bridges.On the basis of seismic analysis theory of bridge, some research on the seismic response spectrum analysis and dynamic time-history analysis will be done in this thesis by taking a Nujiang long span steel truss deck-type railway arch bridge as an example and some conclusions will be obtained through doing a comparison between the results of these two analysis. The following points are the main contents of the research done in this thesis:Firstly, make an overview of the development of long-span steel trussed arch bridge at home and abroad, and analyse its structural characteristics, and then introduces bridge seismic damage and the significance of the seismic design.Secondly, according to the development trend of seismic design of bridge, the paper introduces the current structure seismic design method for the earthquake resistance analysis of the structure provides the theory basis.Thirdly, according to the structural dynamics theory and using the finite element software Midas/Civil, the finite element calculative space model of the whole bridge is established; then the dynamic characteristics of this arch bridge will be calculated. On the basis of dynamic analysis, according to the site seismic safety evaluation report, The response spectrum curve for design is fixed and the anti-seismic analysis is done with the response spectrum theory;At last, the time-history analysis is done with three different seismic waves of each level earthquake, then the results of internal forces of the wave which makes the bridge have the maximum stress are extracted. The paper emphases on the arch and pier’s mechanical characteristics and displacement under the combination of longitudinal, horizontal, longitudinal and verticalseismic, horizontal and vertical seismic. Then makes a comparison of the extracted results with the results of the response spectrum and reaches some beneficial conclusions. Because of the long span, the traveling wave effect which has a great effect on the long-span bridge should be considered in the time-history analysis.