The Research To Comparison Of Seismic Response Of Monotonic Irregular Girder Bridge And The Method Of Damping

This paper refers to an actual irregular multi-span continuous girder bridge in western mountain area in our country, and adopted the MIDAS/Civil finite element software to build analysis model. It has discussed earthquake response of irregular girder bridge in considering the transverse, longitudinal and vertical directions seismic shocks. We emphasized the internal force, shear force and bending moment of the main beam element of bridge and the bottom of pier under the earthquake effect, and adopted time history analysis method to checking acceleration and displacement time history of top of pier. Based on the analysis, it can generalize that response characteristic of high pier and high pier. The destination of this paper based on existing researches generalize the dynamic response of irregular girder bridge combining to actual characteristic of western bridge structural in our country.According to the comparative analysis of two kind of bridges structural model under earthquake function, this article initially draws some beneficial conclusions:At the longitudinal and transverse earthquake effect, maximal internal force and moment appear in main beam adjacent low pier that the pier height difference is large. And the bottom of low pier stress is largest. Contrast to Girder Bridge, stress of irregular girder bridge is complex, especially low pier that the pier height difference is large. Stress of pier bottom and displacement of pier top are bigger at longitudinal earthquake than at the transverse earthquake effect. This paper removes the effect that is caused by the variant of pier height of irregular girder bridge by changing rigidity factor of elastic fixing in bearing. The result indicates internal force of beam adjacent low pier reduces significantly, and it prove bearing has a positive action in antiknock. These theories are beneficial to overall knowing earthquake response of irregular girder bridge and richen in theory of bridge antiknock and significantly serviced to project antiknock design.