Study On The Effect Of Under Substructure Design Parameters On Seismic Response

In recent20years, long-span continuous rigid frame bridge has already obtained the fastdevelopment. This kind of structure can adapt the limits of topography and geomorphology. Itcharacterized the reducing of route length, comfortable steering, wholeness of structure, goodaseismic capacity and construction rapidness. The recent trend of this kind of bridge is theincreasing hight of piers、increasing length of span and more complexity of the planealignment. So continuous rigid frame bridge has got a really nice reception at bridgedesigners.The damage of bridge substructure has become the new characteristics of earthquakedamage form. The earthquake damage is caused by the damage of piers usually, also thedamage of piers cause the collapse of superstructure. The research of the seismic response ofbridge piers play a key role in the research of the response of the whole bridge underearthquake action. The research of thin-wall piers’ mechanical property and it’s influence tothe grider is very little now.This paper studied the influence of different design parameters of substructure to thedynamic performance of the long-span continuous rigid frame bridges.These designparameters includes the section forms and position of the crossbeams of the double thin-wallpiers、variable cross-section of the double thin-wall piers、section form of the double thin-wallpiers and so on.The influence of pile-soil interaction to bridge is studied with finite element method.Alsothe linear elastic analysis of the structure is studied by using response spectrum method. Theresult indicates that the performance of solid crossbeams is superior to hollow crossbeams tothe double thin-wall piers. The change of the position of the crossbeams have an influence tothe seismic response of the structure. The crossbeams is fit for the high piers. Variablecross-section of the double thin-wall piers has its own superiority for the seismic response ofthe structure; The comprehensive dynamic performance of the double thin-wall piers whichwith the solid cross-section is superior to the one with cross-section when these piers have thesame section area. I-shaped cross-section is suitable for the bridge with medium span.The results can give reference to the earthquake resistant design of the long-spancontinuous rigid frame bridges, it can also provide technical basis for conceptual design intoreality in preliminary design stage.