Analysis Of Reasonable Completion State And Seismic Response Of Hybrid Girder Cable-stayed Bridge

Taking a hybrid girder cable-stayed bridge as the engineering background,referring to the design documents and combining the structural characteristics of the main tower,girder and cable,the constraints are determined and the appropriate elements are selected.The Midas Civil program is used as the analysis tool to establish the spatial analysis model of the whole bridge,and the static analysis is carried out.The full text can be divided into three parts.In the first part,based on the influence matrix method,zero displacement method,minimum bending moment method and weighted minimum bending energy method are used to adjust the cable forces of cable-stayed bridges under dead load.The reasonable completed state of cable-stayed bridges is given,and the reasonable cable forces are determined,which is the basis of calculation for later sesmic analysisi.The second part is to compare the influence of pile-soil interaction on the seismic performance of the background bridge,and to establish the consolidation model at the bottom of the tower and the full bridge model under pile-soil interaction,respectively,to analyze the dynamic characteristics of the structure.The influence of pile-soil interaction on the dynamic characteristics of hybrid girder cable-stayed bridge is preliminarily determined.On the basis of the structural dynamic characteristics,the influence of different seismic magnitudes E1 and E2 and different excitation directions on the internal force and displacement of the structure is discussed,so that the effect of pile-soil interaction on the seismic displacement and internal force production of the structure is considered.It has a greater impact.In the third part,in order to further prove the influence of pile-soil interaction on the seismic performance of background bridges,this paper takes the non-linear finite element time-history analysis as the means,and takes the displacement and internal force of key parts of background bridges as the criterion.By comparing the seismic response of tower bottom consolidation model and pile-soil interaction model,the paper gives the seismic performance of background bridges considering the effect of pile-soil interaction.Three groups of artificial seismic waves and three groups of natural seismic waves are used in seismic time history analysis.The displacement and internal force responses of the whole bridge model with pile-soil interaction under different seismic magnitudes E1 and E2 are analyzed by non-linear time history method.The results of seismic internal force and displacement response under various combinations are obtained,and compared with the results of response spectrum analysis to preliminarily determine the response characteristics of the structure under earthquake action.