Geometric Nonlinear Analysis Of Long Span Three Tower Cable-Stayed Bridge

The basic theory of the non-linearity of the cable-stayed bridge is firstly introduced in this thesis, then three principal factors that affect the geometric nonlinearity of cable-stayed bridges are described, which are cable sag effect, large displacement effect and the coupled beam-column effect of bending moment and axial force. Then the finite element analysis method for the non-linearity of the cable-stayed bridges is introduced and the feasibility of several nonlinear solution of geometric nonlinearity is discussed.Taking a long span three tower and single plane cable-stayed bridge of Jinan Jianbang Yellow River Expressway Bridge as the engineering background, the model of space finite element of the bridge is established by using the finite element common software of Midas/Civil. Then the geometric linear and the geometric non-linear static analysis were investigated with each construction stage and the service stage, and the key points and positions were selected for the main research, in this thesis, there are five important construction stages and vehicle load action of the service stage are selected for the emphasis analysis. Every stage is analysed by five loading cases, which contains geometric linear analysis, three geometric non-linear factors effect alone and the total effect together.Therefore, according to the above-mentioned calculation and analysis, the geometric non-linear static performance and analysis method of the long-span three tower cable-stayed bridge were comprehensively understood. Then according to the coMParison between those results, some valuable conclusions are obtained for reference in design of the same type cable stayed bridges.