Application On Construction Control Theory Of Stress-Free Status Methods For Composite Cable-Stayed Bridge

With the increase span of cable-stayed bridge, the construction process is also becoming more and more complex, construction control technology of cable-stayed bridge has become increasingly important.Based on the construction control of Guanyinyan Bridge, this thesis will discuss the Stree-free Status Method from the two aspects of basic theory and practical application. This method mainly control the unstress geometry size of each components of the whole cable-stayed bridge such as the unstress length of cable, unstress geometry of steel girder. The basic point is:as long as the unstress length and unstress curvature of each component in the cable-stayed bridge structure remain unchanged, after the bridge is completed the final status of internal forces and the displacement is the same, and is unrelated to the specific construction process of the bridge. This construction control method offer great convenience to the cable-stayed bridge construction, not only the quality of the project is guaranteed, but at the same time achieve more procedure of the cable-stayed bridge construction could be fulfilled. First of all, introduce the basic theories of Stree-free Status Method, through the theoretical analysis we can draw the basic points of this method, and to know the characteristics and advantages of the Stree-free Status Method,Then disscuss the calculation method of steel girder unstress geometry, the relationship between assembled geometry and unstress geometry, and the calculation method of unstress cable length. And finally, With reference to Guanyinyan Bridge, source of prefabricating error is investigated, and main design influence parameters are distinguished using sensitive analysis of parameters, And steel girder cantilever assembled error is studied,and construction measure to assure steel girder connecting smoothlyis put forward,and then discuss how to put the actualunstress geometry which include error into the calculation model to evaluate the influence of the error in each construction stage and the final stage.