Seismic Behavior Analysis Of Long-span Combined Highway And Railway Cable-stayed Bridges

Through the analysis of bridge damage caused by earthquake,it is found that the damage of long-span bridge in earthquake is serious,which has aroused the close attention of the majority of scholars.However,the long-span cable-stayed bridge plays an important role as a transportation hub.Once the damage occurs,it will cause extremely serious consequences,which will not only bring serious property and personnel losses,but also affect the rescue work.At present,the research on seismic behavior of long-span cable-stayed bridge is not deep enough,so it is necessary to further study the seismic behavior of long-span cable-stayed bridge.In this paper,a large-span steel truss girder cable-stayed bridge is used as the engineering background.The main research contents are as follows:(1)Understand the earthquake damage problem of bridge structure at home and abroad.Introduce the development and structural characteristics of large-span cable-stayed bridge,and to sum up the present situation of seismic research on large-span cable-stayed bridge of highway and iron at home and abroad.Finally,the main research contents of this paper are put forward.(2)The seismic response analysis methods of cable-stayed bridges are introduced,including static method,response spectrum method and dynamic time-history analysis method.(3)This paper introduces the engineering background of the large-span steel truss girder cable-stayed bridge,introduces its structure form and characteristics in detail,establishes the three-dimensional finite element model of space by using SAP2000 finite element software,and analyzes its dynamic characteristics.The rationality of the model is verified,which provides the basis for the seismic response analysis of the long-span highway and railway cable-stayed bridge.(4)In order to analyze the effect of pile-soil action on the seismic response of large-span cable-stayed bridge,the pile-soil action is simulated correctly,the three-dimensional finite element model of space is established,and the reasonable seismic wave is selected.The structural internal force and displacement response of long span highway-iron cable-stayed bridge under earthquake action are analyzed.(5)Based on the seismic response analysis of the large-span cable-stayed bridge,the seismic performance analysis is carried out by using two different damping measures,viscous damping and velocity locking,and the results are compared and analyzed.Finally,reasonable seismic mitigation measures are determined to reduce the damage caused by the earthquake action on the long span highway-rail cable-stayed bridge.(6)Summarize the research contents and corresponding conclusions of this paper,put forward the further research direction of this paper and make a prospect.