Construction Control And Analysis Of PC Cable-Stayed Bridge

Cable-stayed bridge is a kind of high-order statically indeterminate structure. The floor system of cable-stayed bridge is bent and pressured, while the supporting system is in tension. The tower and cable arrangement of cable-stayed bridge is flexible with colorful architectural style. The consruction of cable-stayed bridge is full of difficulty, and the construction process greatly influences bridge linear and internal force status, so the construction monitoring of cable-stayed bridge become a significant research subject.In this paper, the domestic and foreign development of cable-stayed bridge is reviewed, the mechanical characteristics is analyzed, and the construction control theory is briefly introduced. The construction monitoring methods and contents of cable-stayed bridge are focused on with Nanfei River Bridge as the engineering background. The finite model of the bridge is set up by Midas/civil, and the simulation is run on the basis of the construction process. The practice of Stressless Principle in secondary cable-adjustments is elaborated. And the expansion allowance on tension-end anchor head is analyzed by the change of unstressed length of the cable, which provides a theoretical basis for the construction monitoring of the bridge.The influence level of structure design parameters on the largest cantilever status and the completed status of the bridge are analyzed to identify the sensitivity of the parameters. The result helps to intensively monitor the sensitive parameters in construction process. Ensuring a high-precision closure and a finished state which can meet the design requirement.How the changes in construction process affect the bridge structure linearity and the internal force are explored, and a detailed research is conducted on several selected key sections to compare the differences of internal force, deformation and cable force. A reasonable construction project is proposed and verified to ensure both safety and stability of the bridge construction, and fulfill the obligations of construction monitoring.The mechanical characteristics of the construction stages of traction-hanging basket system are analyzed by finite element software Midas/Fea and Dr. Bridge individually. The simulations of segmentary concrete casting and multistage tensioning construction are presented in detail. The Double-Control Method is proposed according to the comparision results, which means to establish the space-entity model of hanging basket and main beam, and contrast that with the model of plane bar system. The method provide linear control of the main beam with much more accurate stimulated data, and also can be applicable as references to the bridges of similar kind.