| This thesis is based on the design of a cable-stayed bridge with special-shaped leaning tower and 70+80+200+80+70m-span. The finite element model of the whole bridge is established by MIDAS/CIVIL, a professional software for bridge engineering. The pile-soil interaction is simulated by centralized parameter method. Seismic reponses of this bridge is analysed by response spectrum method and time history method. Differences of results given by these two methods are compared in order to check their correlation. According to the aseismic isolation bearings, which is used to simulate the nonlinear boundary, the influence of the bearings for bridge is verified by the different structural responses between linear time history and nonlinear time history. Based on the analysis of structural internal force, regular reinforcements for each section on substructure are designed so as to calculate the nonlinear time history analysis. The ductility coefficient can be obtained by analyzing the plastic corner of the most unfaverble section, and the level of aseismic performance is calculated to judge whether it meets the codes or not. Using the large finite element software ANSYS, the whole bridge model is established with shell elements. Then, the most unfavorable loading condition of the longest cable in middle span is calculated to get the maximum principal stress, minimum principal stress and the Mises stress of cable-girder anchorage. The rationality of those stresses for the cable-girder anchorage is analysed, and the corresponding optimized solution is carried out. According to the half-open-vehicle traffic plan, the internal force variation of the opposite side cables and the same side cables is calculated after one of these cables is removed, and the influences of deformation and stress in main girder are analysed to demonstrate the feasibility of cable replacement for the cable-stayed bridge. |
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