| Continuous curved girder bridges are widely used in urban road traffic construction,especially as ramp bridges of urban traffic hub,because of their beautiful linetype and good adaptability.However,in practical application,there are many engineering accidents of continuous curved girder bridges,especially those caused by the prestressing effect of curved continuous girder bridges.In order to analyze the stress characteristics of continuous curved girder bridges,especially the spatial effect of prestressing force,this paper takes an on-ramp curved bridge of a provincial highway project in Xiamen as the background,and studies the spatial effect of prestressing force through finite element modeling.Firstly,the models of straight bridge and curved beam bridge with the same span are established by using finite element software.By comparing the differences of the mechanical characteristics of the two bridges under the same load,the different characteristics of the bridge caused by the existence of curve form are fully understood.Secondly,the mechanical characteristics of curved continuous girder bridges caused by prestressing at different positions of cross section are fully analyzed.In order to study the bearing characteristics of curved continuous girder bridges,two models of widening of double supports and single support of middle pier are set up to change the bearing form of bridges.Compared with the original model of double supports,the bearing characteristics of curved continuous girder bridges are studiedFurthermore,five models of curved continuous girder bridges with the same span but different radius are established to analyze the influence of curvature radius on the mechanical characteristics of curved continuous girder bridges.On the basis of unchanged radius,taking small radius ramp bridge as an example,the influence of different spans is analyzed,and the problem of local small radius caused by local pipeline deviation is also analyzed.Finally,through the simulation of the bridge construction stage,the influence of the tension sequence of the whole bridge’s prestressing tendons is analyzed,and the tension sequence of the prestressing tendons is optimized.The effect caused by the shrinkage and creep of concrete is also analyzed,which provides some guidance for the actual construction. |
