Seimics Analysis Of Composite Girder Cable-stayed Bridge Considering Pile-soil Interaction

With the development of society,people are increasingly demanding for traffic safety and comfort,and the traffic lines are becoming more and more complicated.As bridges are the major structural to crossi obstacles,various types of roads are required to meet the requirements of the terrain.At the same time,due to the frequent frequency of earthquakes and the increase of seismic intensity in recent years,earthquakes and the resulting have received more and more attention from the society.With the use of computers in bridge projects and the improvement of computing capabilities,bridge construction techniques and stress state is also easier for people to grasp.As a modern bridge,cable-stayed bridges are more and more popular because of their large spanning ability and beautiful appearance.It is very necessary to ensure the safety of the bridges under earthquake.This paper relies on the construction of the Yumenkou Yellow River Bridge project in Hancheng,Shaanxi Province,and builds a full-bridge model with the help of the professional bridge analysis software CsiBridge.It considers the pile-soil interaction and analyzes the response of the bridge under earthquakes.The content and results are as follows:1.The historical earthquake records near the bridge site were investigated.Vibration calculation parameters of the soil layer were established based on the borehole test data of the pile foundation and the stratum distribution at the tower of the bridge.2.Established the bridge fixed model and pile foundation model,and compared the dynamic characteristics of the two models;based on this,established the constant "m" method considering the pile foundation,the layered soil "m" method and the consideration Soil liquefaction three methods of analysis,the total of four kinds of models.3.According to the actual geological conditions of the bridge site,the response spectrum curves of the E1 and E2 earthquakes were determined,the vertical and longitudinal,vertical and lateral seismic combinations were respectively set up.The spectral analysis of main towers,pile foundations,and full-section girders was performed on the four models,and the responses of the different earthquake combinations to the bridge structures were analyzed.The differences between the four different models under earthquakes were analyzed.4.Through the PEER website,according to the response spectrum,three seismic time-course recording waves were selected,and each wave was selected for vertical + vertical and vertical + horizontal seismic combinations to analyze the four models.The response of each model under each time curve was compared,and the impact of the differences in seismic waves on the various components of the bridge structure and the differences between the models in the time history analysis were compared.On this basis,two types of seismic analysis methods were performed.Comparing the results,it is concluded that for different components of the bridge structure,the relationship between the two methods is not constant.