Research On Anti-Seismic Behavior Of Long-span Half-Through Railway Arch Bridge

In recent years, earthquake disasters occurred frequently and caused a serious loss of life and property. Under the effects of earthquake, bridges which are the most important transportation lifeline systems are also destroyed. Thus, it is very realistic to do some anti-seismic research on bridges.On the basis of seismic response spectrum 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 long-span half-through arch bridge in Chengdu to Guiyang railway 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:1. According to the structural dynamics theory and using the finite element software ANSYS, the finite element calculative space model of the whole bridge is established;2. Firstly, the dynamic characteristics of this arch bridge will be calculated. Then its first ten mode shapes of vibration and its corresponding frequencies are taken out;3. Secondly, according to the code for seismic design of railway engineering, the response spectrum curve for design is fixed and the anti-seismic analysis is done with the response spectrum theory;4. The time-history analysis is done with three different seismic waves, then the results of internal forces of the wave which makes the bridge have the maximum internal forces are extracted and by comparing the extracted results with the results of the response spectrum, some beneficial conclusions can be reached easily.5. Because of the length of the span, the traveling wave effect which has a great effect on the long-span bridge should be considered in the time-history analysis.6. Finally, in order to find out how much effect the lateral rigidity has on the arch bridge, another two finite element space models of the whole bridge with different shapes of transverse braces are established and time-history analysis is done separately. Some meaningful conclusions are drawn by making comparison among the results of these three models.