Seismic Response And Vulnerability Analysis Of Long-span Rigid Frame Continuous Grider Bridges

Since the reform and opening-up,especially in recent years,China's large span highway and railway bridge construction has made remarkable achievements,we have built a number of novel structure,complex technology,design and construction difficulty and high technology content of large span bridge.The seismic analysis of Rigid frame continuous girder bridge is a complex problem,so different researchers can have different research results.In this paper,based on the true engineering example,the continuous beam bridge of Zhu Jia paper mill is used to built 784 kinds of working conditions to be calculated by using software MIDAS/CIVIL:(1)Based on the platform of AUTO-CAD and OFFICE-EXCEL,using the developing software language VBA to develope " steel beam switching auxiliary assistant system " and " bridge modeling assistant ",then we can use the software to generate MCT file which can be used by MIDAS/CIVIL.It's very convenient for us to use MCT file to establish all kinds of models.(2)Based on the MIDAS/CIVIL bridge structural analysis software,a three-dimensional numerical simulation model of the rigid frame continuous beam bridge of the paper mill is established.The influence of the pile-soil effect on the bridge structure is compared with the pile-soil effect is not considered.(3)Based on the pile soil effect,the difference between the pier height and the pier difference height is changed,and the relationship between the pier height and the pier height difference to the bridge bending moment,displacement and natural vibration period is obtained.(4)A series of studies on the effect of two important parameters,yield ratio and yield strength,on the effect of bridge isolation are carried out in the two wire mechanical model of lead bearing.The range of optimum yield ratio is obtained.The influence of yield strength on the hysteretic curve of supports and the shear deformation of supports is obtained.(5)Through a large number of calculation and analysis,the damage index is defined,and the pier bottom,pier top and support are taken as the calculation target.The equation of displacement and seismic PGA is fitted,and the damage probability corresponding to various situations is calculated.The five kinds of working conditions of pier height difference are calculated to find the optimum anti-seismic pier height difference.