The Static And Dynamic Characteristics And Seismic Response Analysis Of The Super-arge Span Suspension Bridge

In the new century, the study of more than 3000m level large-span suspension bridge is attached the growing importance to designer today. As super-span bridge structure is flexible, its effects of geometric nonlinear are become more obvious. The static characteristics, dynamic characteristics and response are become more complex on the form of bridge, therefore it becomes essential to carry out the research in this field.From the changing cable system by several scholars who do research to increase the stability of the bridge. Design a simple reference to the available information four main span 3000m, 1000m cross-border mega-span suspension bridge. Its structure is as follows : the traditional two main cable suspension bridge; the expand two main cable spacing suspension bridge; the main cables suspenders oblique cross-imposed suspension bridge; three main cable suspension bridge. The designer use finite element software ANSYS to establish the four finite element model of bridges .In the progress of the analysis, the designer analyses static and dynamic characteristics of the bridge and make a comparative analysis. Given these data model in the wind load on the mechanical properties of detailed description, in this paper, to avoid duplication of work, the designer is focus on the response of four models under earthquake loading and makes an analysis. The main conclusions are concluded as follows:1, As for changes of four cable model in the cable system, parabola method and the finite element method are main cable design method .main beam of light steel girder design used commonly achieved good results; three main cable system design of main tower which is compared with the others has a larger differences.2, In the static characteristics, the four models are not very different. In one word, change internal force to the whole cable system of control values greater than traditional cable model; The three main cable suspension bridge has its own unique in cable and tower aspect. In the dynamic characteristics, the models of the natural cycle longer, the vibration mode of torsion and the main tower is late. In the previous 20 rank, Vibration mode of the main cable is mainly accounted for a large share, special cable structure will cause a special type of cable vibration mode.