Study On Construction Control Of The Long-span Prestressed Concrete Continuus Rigid Frame Bridge

The prestressed concrete continuous rigid frame bridge is widely used because of its high strength, lightful line type, convenient and fast construction, long-span ability.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 are safe in construction, and ensure that the girder line shape after the continuous beam bridge be completed and structure internal force accord with the designing requirement, and make the real state that just constructed the bridge in succession conform as much as possible with designed the state, it is indispensable that the bridge construction control.The paper through analysis and summing-up the development of the long-span prestressed concrete continuous frame bridge and the construction control techniques in our country and abroad, to introduce and summarize the characteristics and construction method of the prestressed continuous rigid frame bridge. The continuous rigid frame bridge in Bao—long freeway in Yunnan as the project background, to study the prestressed force construction in cantilever pouring, the closure sector construction of technology and the parallel truss basket structure design and choice.This text combines the project practice of the continuous rigid frame bridge, has studied the process of the linearity control and the stress control in this bridge cantilever pouring construction, to analyze on detailed the exertion of the control theory in the project practice. Applications large-scale calculation software MIDAS/CIVIL in the bridge to imitate and analyze the cantilever segmental construction, to adjust and control each constructing stages. In the line shape control, through simulation analyze and calculating, to gained pre-camber of construction and pre-camber of completed stage, and propose the calculation formula of the elevation of the form board, to achieve the design linearity through the closure result. In the stress control, calculated and 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. Finally, this paper puts forward a scheme of long-distance wireless monitor system for long-term status of bridge. This is a comprehensive static data collecting system with full-automatic survey of unmanned-keep watch and wireless data transmission. It can be widely used on many kinds of project fields, such as bridge, architecture, railway, dam, etc.