Abstract:In order to explore the seismic response law of continuous rigid-frame bridges in high-intensity areas, firstly, taking a long-span continuous rigid-frame bridge in a high-intensity area in Guizhou as the research background, a three-dimensional spatial finite element model is established according to MIDAS Civil 2019, and the structural natural vibration characteristics of the bridge are explored. Secondly, based on the site conditions of the bridge, combined with the relevant specifications, the target response spectrum and artificial seismic wave are given. Finally, the results of response spectrum and time history analysis are given, and a detailed comparative analysis is made. The research shows that under the premise of ensuring the strength and stability, the long-span continuous rigid-frame bridge located in high intensity areas should have certain restraint release in the longitudinal and transverse directions, which is conducive to the structural deformation to absorb the seismic energy, and then reduce the seismic damage. Under the working condition of response spectrum calculation, the maximum longitudinal displacement and transverse displacement are 0.304 m and 0.381 m respectively, which are related to the direction of seismic excitation. The vertical displacement is about 0.05 m, which has little relationship with the direction of seismic excitation. By comparing and analyzing the calculation results of response spectrum and time history analysis, it can be seen that the calculation results of time history analysis are larger than the calculation results of response spectrum on the whole, which also meets the requirements of relevant specifications.
