The Seismic Response Analysis Of Continuous Rigid Frame Bridge With Bottom Plate Level Layout

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 with high piers.The double-layer continuous rigid-frame bridge with the cable level layout in bottomplane, is a new structure based on the existing continuous rigid frame bridge diseases,which the seismic response studies of is inadequate. To study the seismic responsecharacters about the continuous rigid frame bridge with with bottom plate level layout,to reasonable seismic design of such bridge structure, it is important theoretical andpractical engineering value to promote its wider application in bridge project.This paper describes the basic theory of seismic response analysis, based on the LongTeng Bridge in Yunnan Province as engineering background, researched the seismicresponse characteristic of continuous rigid frame bridge with the bottom cable levellayout, major research as follows:1.With professional finite element software Midas/Civil to establish the continuousrigid frame bridge with the bottom cable level layout finite element model, analyzed itsvibration characteristic.2.To Consider the along the bridge and vertical, horizontal and vertical seismic action,and solve the seismic response spectrum analysis of the structure fore; due to terrainconditions, it’s here obtained the ultimate capacity of some special scetions in l#,2#pierand main girder to compare, it’s aim to observe the degree of the enable materials playmaximize performance.3.To Consider the along the bridge and vertical, horizontal and vertical seismic action,to solve the structure of the internal forces with the method of time historyanalysis.Based on the bridge model of Long Teng bridge, it’s using the El－Centrowave closing to the natural period and peak acceleration with site. And the calculation of the seismic wave peak acceleration has been adjusted accordingly which could adaptto the actual needs of the bridge design ground motion. To explore the differences ofthese two methods, compared with the solution of them.4.Based on the concrete bridge site situation, change the height of entity segment partof2#pier and creating a new model, using response spcetrum analysis to find the effectwhen changing the height of entity segment part of2#pier, and the internal forceschanges of the structure.5.Based on the form of cross-section of the Long Teng Bridge, changing thecross-section to the ordinary box section, and creating a new model, using responsespcetrum analysis and time history analysis to find the effect when changing the form ofsection, and the internal forces changes of the structure.6.According the seismic response analysis results, reasonable proposals were putforward to the continuous rigid frame bridge seismic design with the bottom cable levellayout.