Effects Of Construction Stage Errors On Long Term Performance Of Long Span PC Continuous Beam Bridge

Bridges as the main fabricators to across route barriers are widely used in theconstruction of transportation infrastructure, in which large-span prestressed concretecontinuous girder bridges constructed accounts for a significant proportion in China. In recentyears found that excessive mid-span deformation, beam cracks and other diseases of largespan beam bridges occurred after a number of years in service. In this article, errors from theconstruction phase for the first time have an effect on long-term mechanical properties ofbridge structure about this problem. First of all a reasonable classification of the error in theconstruction stage, followed by considering different types of errors on the long-term effect ofinternal force and deformation of bridge structure, with a view to put forward reasonableproposals on bridge construction and design.Construction phase errors can be generalized into construction quality problems andconstruction errors, construction quality problems can be divided into exposed quality issuesand potential quality problems; construction errors can be divided into standard errors anderrors in specification is not provided, different types of construction error on long-termmechanical properties of bridge structures with varying manner and extent. This article isrelated to the height difference of closure and two errors about the shrinkage and creep.Different models of shrinkage and creep for the calculation of long-term internal forceand deformation of the structure vary considerably, calculation of existing norms in generalsmaller than other specifications. Due to less current study of shrinkage and creep modelsunder non-standard conditions and therefore does not exclude this is a cause for long-termdisease of bridge.Loads age effects on long-term internal force and deformation of bridge structures: as forlarge span beam bridges, main span over more sensitive than side, main Pier top stress ratiomore sensitive than side of Pier top stress, theoretical data show that by the load age of theexisting norms in our country result in deviations from the design values of structural afterdecade of shrinkage and creep within5%.Height difference of closure on the long-term effect of internal force and deformation of bridge structure increases with the forced height difference closure grows, theoretical analysisshows that enforced closure is beneficial for the control of long-term deflection, but adifferent impact on structures on both sides: on the ballast side, forcing closure of side-spanupper-Flex, Pier pressure stress decreases and just the opposite on the other side, as a whole,forced closure on the heavy side for a greater impact. Data indicate that for hundreds ofmeters long span bridge while forcing height difference is less than5cm, ensures that theirimpact on the structure of long-term mechanical properties is less than5%.