Research Of Construction Control Of Cable-stayed Bridge With Single Cable Plane And Tower

Cable-stayed bridge is a kind of highly statically indeterminate structure that its design and construction are very difficult. For cable-stayed bridge of compositive girder by cantilever and segment construction, as a result of the effects of temperature difference, concrete shrinkage and creep during construction course, stress condition of conjugation site between concrete and steel box girder is very complex. In addition, adjusting range of internal force and alignment is very finite after construction. So rigorous construction control is very important for realization of design scheme. Taking Ronghu Bridge of Wuxi city as an example, this thesis studies the optimization of cable tension under the action of dead loads, the process control of cantilever construction and the three-dimensional finite element analysis of main tower.Aiming at reasonable stress distribution of tower and girder, reasonable alignment of bridge, FEM computation and optimization analysis are combined to determine the reasonable cable tension. The result of the cable tension of Ronghu Bridge indicates that this method is very simple, effective and applicable. According to calculation formulas for the end elevation of cantilever at each step of cantilever construction, we strictly controlled cable tension and fronted elevations of box girder during the process of construction. These measures ensured that the construction of this bridge had completed successfully.The three-dimensional model of the main tower was established with block element and membrane element to analyze its distortion. Compared with spatial analysis, planar analysis leads to obvious errors of model, especially the stress errors of key components. The spatial analysis can obtain better results than planar analysis.