Continuous Rigid-frame Bridge Construction Control Theory And Application Analysis

The prestressed concrete continuous rigid frame bridge is widely used becauseof its high strength, lightful line type, convenient and fast construction, long-spanability.The long-span prestressed concrete continuous rigid frame bridgeadopts symmetrical cantilever pouring construction often. During the process of thebalanced cantilever construction, the bridge structure is influernced by variousfactors, such as shrinkage, creep and temperature change of concrete, designparameter and actual difference，construction error, survey error, and so on.Adopting the cantilever pouring construction like this must result in verycorriplicated change of the internal forces and displacements in the bridge. In orderto guarantee that the construction quality of the bridge and are safe in construction,and ensure that the girder line shape after the continuous beam bridge be completedand structure internal force accord with the designing requirement, and make thereal state that just constructed the bridge in succession conform as much as possiblewith designed the state, it is indispensable that the bridge construction control.Based on the analysis summary of domestic and foreign development of largespan prestressed concrete continuous rigid frame bridge and the construction controltechnique, the characteristics and methods of the construction control of long spancontinuous rigid frame is introduced. Hydropower station of Dadu river mountainS211and traffic reconstruction project A of ShenYue river bridge as the engineeringbackground, this paper expounds the grey system theory and establishes a predictionmodel GM (1,1). It will be regard ShenYue river bridge project as a grey system. Inthis article, an example is a predicted calculation of ShenYue river bridge of9thpiece of box girder in5th pier using GM (1,1) model in order to forecast the changeof9th piece of value calculation of deflection. It concludes that the next phase oftemplate reserves camber. Applications large-scale calculation softwareMIDASICIVIL in the bridge to imitate and analyze the cantileversegmental construction, to adjust and control each constructing stages. In the lineshape control, through simulation analyze and calculating, to gained pre-camber of construction and pre-camber of completed stage, and propose the calcvelationformula of the elevation of the form board, to achieve the design linearity throughthe closure result. In the stress control, calculated and to gain the box girder theorystress in each constructing stages by the model, through comparative analysis, it isidentical basically to survey stress value and theory stress value, to achieve thepurpose of the stress control in this bridge.According to the practical engineering experience, some useful conclusionsabout the continuous rigid frame bridge and experience for the same type of bridgeconstruction control have a certain reference.