Analysis Of High Pier Seismic Ductility Of Irregular Bridges Based On Opensees

Influenced by topography, the western China must build many high piers of long-spanbridges when constructing lots of road and rail infrastructure, the bridge belongs to the typicalirregular bridge, there is no relevant seismic specification that can be directly used, lessresearch on this kind of bridge seismic ductility, far less than the actual engineering needs. Inorder to analysis of high bridge pier ductility behavior under seismic excitation, this thesismainly done the following work:Three pier models based on elastic-plastic fiber beam-column elements are establishedthrough OpenSees software,Using the incremental dynamic analysis method to study seismicresponse of the pier models,the nonlinear static push down method as part of the comparisonand analysis. It is concluded that the ductility performance of the pier columns under differentseismic wave excitation has a bigger difference, using the incremental dynamic analysismethod to evaluate pier displacement ductility capacity is more accurate.Due to the top of the pier of birdge structure is constrainted to a certain degree by theupper structure,establishing a elastic-plastic finite element model of long span continuousrigid frame bridge.Considering frequency spectrum characteristics obvious differencebetween the long-period seismic waves and ordinary seismic waves,so two long-periodseismic waves and three ordinary seismic waves are input to the long span continuous rigidframe bridge along the bridge and cross the bridge respectively. Aanlysising the pier ductilitybehavior respectively fluenced by long-period seismic waves and ordinary seismic wavesalong the bridge and cross the bidge excitation.Getting that: When long-period seismic waves were input to the structure in twodirections, despite the acceleration peak value is much lower than ordinary seismic waves,structure has entered into a state of the corresponding yield and limit state. Pier ductilityperformance has a significant difference between the long-period seismic wave and ordinaryseismic wave when respectively input the seismic wave to the structure aong the bridge,butthere is no obvious difference with seismic wave excitation cross the bridge.