Mechanical Invesitigation Of The Tower Construction System Of Double-Tower-Connected Cable Stayed Bridge

The cable-stayed bridge is a kind of indeterminate flexible structure with many redundant degrees of freedom, which consists of three basic members: towers, girders and cables. The tower of Yongjiang river cable-stayed bridge is the Double-Tower-Connected Structure that is a new complex structure system. Studies on structural behaviors including static behaviors, dynamic characteristics and seismic responses of the Double-Tower-Connected Structures are given systematically in this thesis, which could help to a deeper understanding of the basic conception for the Double-Tower-Connected Structures. And the thesis also establishes a foundation for further researches and provides a reasonable design guideline.The basic element of finite element method, especially the bridge static analysis of finite element method is expatiated, and the finite element method software for bridge analysis is researched. A structure computation model for analyzing the Double-Tower-Connected Structures system has been founded based on software MIDAS, and the presented model is applied to study the static behaviors, dynamic characteristics and seismic responses of the Double-Tower-Connected Structures. The static behaviors of the Yongjiang river cable-stayed bridge has been analyzed with finite element program MIDAS under specified loads. And in the matter of dynamic analysis, the dynamic characteristics have been compared between the double-tower and the Double-Tower-Connected Structures, including the basic frequency and vibration modes. And then the seismic response analysis of Double-Tower-Connected Structures is carried out. The mechanical characteristic and the deformation behavior of this structure subjected to seismic action are analyzed deeply. The study is able to provide reliable evaluations for bridge design to bear earthquake.After calculation in this thesis, some conclusions on characteristics of Double-Tower-Connected Structures are summarized, which are useful for project design and further researches.