Research On Construction Control Of Three-span Prestressed Concrete Continuous Rigid Frame Bridge

The continuous rigid frame bridges with pier beam consolidation, not only have no expansion joint just like continuous beams and are comfortable to drive on them, but also have no bearing and don't need system transform as the T Rigids do. And they are convenient to construct. So the continuous rigid frame bridges are bursting with vitality. In recent years, continuous rigid frame bridges become the best option and take up a great proportion in mountainous area stabling Expressway of large span pre-stressed concrete bridges. Among them, the small span of three-span continuous rigid frame bridges are widely used.In this paper, the Yang Bay Bridge is taken as an example, and the three-span (50m+ 90m+50m) pre-stressed concrete continuous rigid frame bridge of a highway project is focused on, In the process of cantilever construction, factors including the creep and shrinkage of concrete pre-stressed tensioning, temperature, phase ii constant load, loading age, etc., which affect linear and internal force of the main beam are studied. The elastic modulus of concrete, concrete bulk density, strand elastic modulus of the Yang Bay Bridge theory of pre-cast high value, Comparativing analysis of the monitor results are also specialized to ensure that the main beam and the linear control section stress. Therefore the specifications and design requirements are achieved. The results show that:Among the factors which cause changes of camber, concrete bulk density impact greater, then strand elastic modulus. In the process of continuous rigid frame bridge cantilever construction, deflection caused by the pouring of concrete is up to 13mm, deflection caused by pre-stressed up to 12mm, and down-warping caused by hanging basket moving maximizes to 4mm The closure error of midspan is 8mm, the closure error of 16# side pier span is 4mm, and the closure error of 15# pier side span is up to 25mm. After processing by adding a counterweight, the closure error of 15# pier side span 3mm, error of closure section of others are not more than 10mm and fit regulatory requirements well. Research results of Yang Bay Bridge could greatly provide reference for bridge construction control.