Research On Theory Of Construction Control For Long-span PC Continuous Rigid Frame Bridges And Application

Due to the Reform and opening-up, the rapid development of the national bridge construction in our country not only improve the quality of people's life, but also infuse vigor and enthusiasm into the recovery of national economy in the current situation of the global economic downturn. In the large number of bridge structures, in particular, the pre-stressed concrete continuous rigid-frame bridge with its own characteristics is given much favor by designers.The long-span prestressed concrete continuous rigid-frame bridge adopts symmetrical cantilever pouring construction often. During the process of the balanced cantilever construction, the bridge structure is influenced by various factors, such as shrinkage, creep and temperature change of concrete, design parameter and actual difference, construction error, survey error and so on. Adopting the cantilever pouring construction like this must result in very complicated change of the internal forces and displacements in the bridge. In order to guarantee that the construction quality of the bridge and bridge construction are safe, and ensure that the main girder line shape after the continuous beam bridge is completed and structure internal force accords with the designing requirement, and make the real state that just constructed the bridge in succession rigid-frame conform with the designed state as much as possible, it is indispensable that the bridge construction control is done.This text, on the basic of the construction of Tianluo Bridge of Wen Zhou-Fu Zhou Railway Passenger Dedicated Line, has studied the process of the linearity control and the stress control in this bridge cantilever pouring construction, to analyze in detail the exertion of the control theory in the project practice. We apply large-scale calculation software MIDAS/CIVIL in the bridge to imitate and analyze the cantilever segmental construction, to adjust and control each construction stage. In the line shape control, through simulation analyzing and calculation, we can gained pre-camber of construction and pre-camber of completed stage, and propose the calculation elevation formula of the elevation of the form board, to achieve the design linearity through the closure result. In the stress control, we can calculate to gain the box girder theory stress in each constructing stages by the model, through coMParative analysis, it is identical basically to survey stress value and theory stress value, to achieve the purpose of the stress control in this bridge. And the factors which influence the alignment control of PC continuous rigid frame bridges, such as concrete creep and shrinkage, jacking force, age difference, are analyzed. The application of "Adaptive Control" theory in construction control is discussed. The data of stress measurement is analyzed based on the concrete creep and shrinkage theory.