Dynamic Response Analysis Of Continuous Rigid Frame Bridge Under Non-uniform Excitation

In recent years,China’s high-speed development of transport,continuous rigid bridge as an important form of structure,in the field of bridge engineering has been widely used.Because of the engineering sites’topography and other factors in Southwest China,the span of the bridge is getting bigger and bigger,the pier is getting higher and higher.Because the region is relative active region in seismic activity,the bridges are often striked by the earthquakes.The rescue after the earthquake will be bothered once the main bridges are damaged under the strong motion.But there are no conclusions on the seismic response and its characteristics of continuous rigid frame bridges under non-uniform excitation,some problems about it are still waiting to study.So the numerical analysis of the the seismic response of continuous rigid frame bridges under non-uniform excitation were done,to study the seismic response and its characteristics.This study included several work mentioned below:（1）The seismic response analysis methods and research status were summarized in the thesis,according to the studies in China and oversea.（2）The finite element model of Chongqing Qijiang Bridge were established by the FEM software Midas Civil,and the modal analysis of two different models were analyzed and their dynamic modes were compared.（3）The response spectrum analysis of the finite element model of long span continuous rigid frame bridge under E₁ earthquake is carried out.The structural response of the bridge to the vertical bridge,the transverse bridge to the vertical bridge is calculated and the seismic response is analyzed.It is found that the bridge bridge has an absolute contribution to the bridge bridge displacement D_x,the in-plane shear force F_z and the in-plane bending moment of the bridge,and the transverse bridge to the bridge of the bridge to the displacement of the bridge D_y,Force F_y,face outside moment M_z has an absolute contribution.（4）Combining the site conditions and the seismic zoning map of the bridge site to select the appropriate seismic wave,the time-history analysis of the bridge is made,and the combination of the various seismic action combinations at different levels of seismic acceleration is summarized.The internal force and displacement of the bridge structure show a monotonically increasing or monotonically decreasing trend due to the difference of the input angle of the horizontal seismic acceleration.Under the action of the bridge to the earthquake,the bridge internal forces and displacements of the structure exhibit symmetry due to the difference in the input angle of the horizontal seismic acceleration.（5）Considering the traveling wave effect,the same seismic wave is input according to different wave velocity,and the non-uniform excitation analysis of the bridge is carried out.At the same time,the influence of different spectral characteristics on the seismic response of the bridge is considered and the results of the same incentive are carried out.In contrast,when the apparent velocity is 100m/s and 200m/s,the hysteresis effect is obvious.With the increase of the apparent wave velocity,the hysteresis effect is weakened and eventually converges to the result of consistent excitation.