Study On Mechanical Behavior Of Long-span Cable-stayed Bridge With Composite & Hybrid Girder In Construction Stage

In recent years,a new type of composite-hybrid girder cable-stayed bridge has been widely developed and applied because of its spanning capacity and economic benefits.In order to ensure the safety and engineering quality of this type of cable-stayed bridge in the construction process,it is necessary to study the reasonable construction control model of this type of cable-stayed bridge.In view of the structure and material characteristics of this type of cable-stayed bridge,taking Nanxi Yangtze River Highway Bridge as the engineering background,the applicability of the composite girder simulation method in the construction control model of the composite girder cable-stayed bridge and the influence of concrete shrinkage and creep on the composite-hybrid girder system cable-stayed bridge are analyzed,and the suitable ones for this type of cable-stayed bridge are obtained.The construction control model and the influence of concrete shrinkage and creep on the internal force and alignment of the structure.The main contents of this paper are as follows:(1)Analyse the mechanism of the double element simulation method of composite girder,and optimize the double element simulation method based on numerical examples to improve the accuracy and efficiency of calculation.Based on the research results of the two-element simulation method,the applicability of the method in the construction control model of composite girder cable-stayed bridge is analyzed.(2)To study the effect of shrinkage and creep of concrete on the internal force and deformation of cable-stayed bridges with composite girders,including the displacement of bridge towers caused by shrinkage and creep of concrete main girders and concrete decks,the variation of internal force and alignment of main girders,and the internal force redistribution rule between steel girders and concrete slabs on the cross section of composite girders.The reasonable installation time and preparation time of concrete bridge deck are also studied.