Seismic Response Analysis Of Long-span Continuous Rigid-frame Bridge

Bridges are an important part of lifeline projects.The disaster of bridge caused by the earthquake is serious.Prestressed concrete continuous rigid-frame bridge is a widely used type of bridge,studying the seismic seismic response of bridge is good for the bridge design and reinforce.In this paper,by taking a five-span prestressed concrete continuous rigid-frame bridge as engineering background,the response of spectrum analysis and time-history analysis is studied.And give some advice for engineering construction of the bridge.Major work and conclusions are as follows:(1) The dynamic model is established by ANSYS considering the frequency and period of the bridge.The top 20 of the frequency reduced 22%after considering the pile-soil interaction.(2) The seismic responses of bridge is numerically simulated considering spectrum.Pile-soil interaction of rigid-frame bridge affects on the displacement and internal forces.Especially for the displacement,axial force,horizontal bending moment of short pier(Pier 1,Pier 4) and vertical bending moment of the high pier (Pier 2,Pier3).By doing so,reocognize the soil-foundation-structure interaction of bridge structures is very important.(3) The seismic responses of bridge is numerically simulated considering coincident earthquake excitation and compared with the result under the response of spectrum.The results are generally similar than the result under spectrum analysis,on the whole,the response spectrum results are more conservative than time-history analysis.(4) The seismic responses of bridge is numerically simulated considering uncoincident earthquake excitation.Multi-support excitations of rigid-frame bridge affects on the displacement and internal forces. (5) The seismic responses of bridge is numerically simulated considering traveling-wave effect.Traveling-wave effect is good for the rigid-frame bridge.Tt is certain that long-span bridges should be consider multi-support excitation and traveling-wave effect.(6) The effects of the earthquake of rigid-frame bridge is mainly embodied in the bottom and the top of the piers.So should be pay more attention to strengthening the capacity of the piers.And take some measures for reduce the seismic response.