Construction Control Of Long-span Continuous Prestressed Concrete Beam Bridge

In the last two decades, with the development of the communications, long-span prestressed concrete bridges have found more wide applications. At the same time, when such bridges are under construction, people put great emphasis on its construction control in order to guarantee the safety. The merits, hard to deform, good structure rigidity and simple maintenance and so on, place continuous bridges on a good competitive position among modem long-span bridge structure. Then, It is necessary to make further research on such bridges' construction technology.In the process of construction control, accurately searching for the rules of deformation of concrete's shrink and creep is one of the crucial projects. When we monitor bridge's stress, it is necessary to remote the influence of concrete's shrink and creep on measured value. Due to concrete's poor heat conduction, the solar radiation and the rise of atmospheric temperature will make concrete box girder cause different heat distribution. This phenomenon principally reflects on the vertical direction of box girder's section. Temperature changement has very big influence to the stress of box girder. As to the section of the base area of box girder of the cantilever arm, temperature changement has larger influence upon upper stress than upon down stress.Combining the construction of the GanJiang bridge, on which across the railway siding which specially used by Jiangxi Fengcheng Electric Power plant, the article make research in the following four aspects:1. By using the analysis system of bridge construction, analyze stress situation of the primary part of GanJiang bridge when it is under construction.2. On the basis of the theory of grey system and of the modern predictive control, combining the construction features of the long-span continuous bridge, propose grey predictive control system. When building GanJiang Bridge, putting the theory into practice and testing its validity.3. Analyze the effect of concrete's shrink and creep exerts influence on the stress testing of long-span bridge.4. According to datas of temperature got from spot testing, analyze the temperature distribution on respective section: vertical direction, lateral direction of top and bottom of box girder, and of ventral shield, making further analysis of heat load's influence to the stress situation of concrete box girder. Such kind of heat load caused by effects of solar vadiation .