Research On Dynamic Characteristics And Seismic Of Multi-Span Bowstring Arch Bridge Of Concrete-Filled Steel Tubes

In recent years, tied concrete-filled steel tubular arch bridges have reached a greatdevelopment in our country and been used in railway gradually.Because the history of railwayTied concrete-filled steel tubular arch bridges is short,with amount small,the date aboutsecimic study is few.Railway bridges require higher security， more comfortable andhigher-density operation than other bridges.So, the study of the railway tied concrete-filledsteel tubular arch bridges with large span is an urgent task.In the engineering background of super large bridge over SongHua river (with spans77m+156.8m+156.8m+156.8m+77m) in HaQi railway,an elaborate FE model of midas wasbuilt for analyzing dynamic characteristics of bridge structure,especially to analy the arch ribsand piers.The paper focus main research contents as follow:Firstly, to finish the elaborate FE model of midas about super large bridge over SongHuariver, and to analysis dynamic characteristics of bridge structure.Secondly, to carry out response spectrum analysis of super large bridge over SongHua river,which analyes the seismic response under just one orthogonal ground motion and three kindsof different two-dimensional orthogonal ground motion working.Thirdly, to carry out elastic time history analysis of super large bridge over SongHua river,which takes El-Centro, Taft and Taft, ofen use in international. Then compare the result ofelastic time history analysis with the response spectrum analysis under three kinds of differenttwo-dimensional orthogonal ground motion working.Fourthly, to carry out elasto-plastic time-history analysis of super large bridge overSongHua river under El-Centro seismic wave working in axial direction of bridge.Afterlearning about the seismic response of the bridge under earthquake intensities7, it is notdifficult to find out which part of the structure is easy to enter plastic state.Lastly, based on the fourth research, bringing friction pendulum supports to the bridge.Compared the seismic response with spherical-steel supports’, finding out the effect of thereplacement of friction pendulum supports.Through of studying these questions above, we will make a further understanding aboutdynamic characteristics of super large bridge over SongHua river.Besides, the mostunfavorable condition of two-dimensional orthogonal ground motion for the bridge,and theefficiency of friction pendulum supports,then putting forward some suggestions on bridgedesign.