Study On Seismic Performance Of Long-span Continuous Rigid-framed Bridge

Continuous rigid frame bridge has the advantages of long span,reasonable forcedistribution,and strong adaptability ect. It has become the prefered choice in the areawhere is full with deep groove and other complex terrain.Continuous rigid frame bridgeas a lifeline engineering plays an important role in the earthquake rescue.Because of thelong span,the high piers with different heights,its dynamic characteristics is also muchcomplicated.Currently,the design codes can not meet this type bridge seismic designrequirements,so the study on seismic performance of continuous rigid frame bridge hasgreat significance for ensuring the seismic safety.In the dissertation，the seicmic response of the long span continuous rigid framebridge with high piers is studied.The contens are as the following.①On the basis of summarizing continuous rigid frame bridge seismicresearch,finite element models are established respectively for the two programs of theBiyun Bridge. the linear seismic response is calculated by response spectrum and timehistory method,and the seismic response of the bridge with different pier types arecompared.②Model of the bridge with single thin wall piers which is set up by fiberelement,is analyzed by Pushover method with different lateral force distributionpatterns.The difference of capability curves in the different force distribution modesare compared.③Adopting fiber element model，the nonlinear seismic responses eismic responsesalong the longitudinal and transverse bridge is analyzed by the nonlinear dynamictime-history method，and characteristics of the nonlinear seismic response considersthe vertical seismic ground motions is analyzed,then camparize the results withunconsiders the vertical seismic’s.Then the impact to the nonlinear seismic responseunder vertical ground motion is discussed.④The seismic performance of the bridge is evaluateed by IDA analysismethod,using a multiple earthquake waves.And seismic responses of the bridge isanalyzed further,applicated the IDA method.Then the IDA capability curve andpushover curve are compared,and the applicability of the two methods on the highcontinuous rigid frame bridge are also discussed.