Analysis Of Dynamic Characteristics And Seismic Response Of Five Span Continuous Steel Box Arch Bridge

Steel arch bridge are widely used in construction in China with its high carrying capacity, spanning capacity, beautiful appearance and convenient construction, etc.Compared to other types of bridges, the research of dynamic characteristics and seismic response analysis of steel box arch bridge is less. China is an earthquake-prone country, as an important part of the life-line engineering, the research of the seismic performance is particularly important. In this paper, the finite element model of a five span continuous steel box tied arch bridge is established by using the finite element software Midas/Civil to study its dynamic characteristics and seismic response analysis. Mainly to carry out the following work:(l)This chapter describes the overview of the development and Seismic Research of the steel arch bridge, and explains the phenomenon of earthquake damage of the bridge structure.(2)After a review of a large bridge seismic literature,the basic theory of seismic study is summed up,and the method of bridge dynamic characteristics and seismic analysis is described,the advantages and disadvantages of the different methods is compared to provide a theoretical basis of the dynamic characteristics and seismic response analysis of arch bridge.(3)The finite element model of a five span continuous steel box tied arch bridge is established, some vibration characteristics is obtained with the analysis of the natural frequencies and features of mode shapes to provide the basis for the following dynamic analysis.(4)According to the project survey and design requirements,the response spectrum curve of seismic analysis is determined,the seismic response of arch bridge under seismic loads is obtained from the horizontal, vertical and vertical direction on the five-span continuous tied arch bridge,as a preliminary analysis of the bridge seismic response.(5)Seismic waves is input from the three directions of horizontal,longitudinal,vertical, horizontal and vertical orthogonal combination, longitudinal and vertical orthogonal combination with time history analysis method.it is comparative for the displacement and internal force response under the control of the direction and composition of different seismic wave input to get some useful conclusions.