Research On Stability And Seismic Behavior Of Long Span Continuous Rigid Frame Bridge With High Piers

With the development of reform and opening up,China’s economic is advancing to higher levels.What’s more,China’s transportation industry is also developing rapidly.Under the background of the West Development Strategy,high-pier-span continuous rigid frame bridge could adapt to the complex terrain in the mountainous area of Midwest China.Therefore,it is widely developed.With the increase of span and pier height,the stability and the Seismic performance of the bridge becomes more and more important.Based on the background of the construction process of Kuangjiaao Bridge in Xuan’en County,Enshi Autonomous Prefecture,Hubei Province.Combining relevant specifications,this paper introduces the general situation of the bridge engineering,analysis the stability and influence factors of the bridge under the different circumstances.First of all,combined with the research status of stability at home and abroad,this paper introduces two kinds of stability problems of the structure and analyzes them by taking the compression bar as an example,then,summarizes three common methods to solve the critical load.The energy method and the finite element method are used to calculate the critical load of the main pier under dead weight respectively,and compared the results,The calculation error is less than 10%.Secondly,using large bridge established special finite element software-MIDAS/Civil 2015 to set up simulation model of the Kuangjiaao bridge,and analysis the construction simulation.Then,the analysis focus on construction three stages of the highest pier piers,maximum cantilever construction stage and bridge built state.It is concluded that under the condition of different load combination of buckling characteristic values.When analyzing the stability of bare pier stage,the influence of geometric nonlinearity on the stability is taken into account.It is found that the results of non-linear analysis are closer to the actual engineering situation.The stability analysis results of each construction stage show that the stability of bare pier stage,maximum cantilever stage and completion stage all meet the requirements,and the maximum cantilever state of the bridge is the most disadvantageous stage in the construction process.Finally,the seismic design concepts and codes of bridges implemented in China at present are introduced,and the seismic effects in three directions are considered comprehensively,the seismic response analysis of the finite element analysis model was carried out by using the response spectrum method and the linear time history method under the action of the E1 earthquake.