The Seismic Analysis Response Of Asymmetric Continuous Rigid-frame Bridge

With the rapid development of transport in China, more and more continuousrigid-frame bridges have been widely applied to the practical engineerings. Thecontinuous rigid-frame bridges with high piers, which have an enormous advantage infour aspects, economy, applicable, safe and beautiful, especially in the Southwest andNorthwest,where the ground condition is poor and the terrain is very tuff. In recentyears, frequent earthquake, the most severe natural disaster in world,attracted people’sattention again. While earthquake frequently occured in the areas, and the earthquakedisaster data about this kind of bridges is not abundant. So, it is very important to studythe seismic response of the continuous rigid-frame bridge.As a transit hub for road,the bridge has different sesmic requirements from otherbuildings.When the earthquike happen,the bridge is very important to maintain thesmooth flow of traffic lines;for the bridge cost is high and repairment is hard andexpensice,to minimize the damage is also necessary. This paper contrast therequirements of domestic and international norms on the bridge seismicperformance,suggest that our current bridge seismic classification can not meet therequirements of performance-based seismic design, but also not consistent with thetechnical and economic condition.This paper presents a new idea of bridge seismicclassification which based on the importance of the bridge site.After that, This paperdescribes the basic theory of seismic response analysis, based on the Shu Di Bridge inYunnan Province as engineering background, researched the seismic responsecharacteristic of continuous rigid frame bridge, major research as follows:①. Establish the continuous rigid frame Shu Di bridge finite element model Withprofessional finite element software Midas/Civil, analyzed the vibration characteristic.②.2.To Consider the along the bridge and vertical, horizontal and vertical seismicaction, and solve the seismic response spectrum analysis of the structure fore; due toterrain conditions, it’s here obtained the ultimate capacity of some special scetions in l#,2#pier and main girder to compare, it’s aim to observe the degree of the enablematerials play maximize performance.③. To Consider the along the bridge and vertical, horizontal and vertical seismicaction, to solve the structure of the internal forces with the method of time historyanalysis.Based on the bridge model of Shu Di bridge, it’s using the Taft wave closing tothe natural period and peak acceleration with site. And the calculation of the seismic wave peak acceleration has been adjusted accordingly which could adapt to the actualneeds of the bridge design ground motion. To explore the differences of these twomethods, compared with the solution of them.④. Based on the concrete bridge site situation, change the height of2#pier andcreating a new model, using response spcetrum analysis to find the effect whenchanging the height of2#pier, and the internal forces changes of the structure.