Construction Process And Prestressing Parameter Analysis Of The Prestressed Concrete Composite Continuous Box-Girder Bridge With Corrugated Steel Webs

As a new kind of bridge appeared over the last decades, prestressed concrete(PC) composite box-girder bridge with corrugated steel webs has a great deal of advantages, such as light self-weight, high effective prestressing system, short construction period, beautiful shape, etc. As an unique bridge structure, each part of the box-girder has specific mechanical behavior and the web would not crack. It has gained extensive research and application in France and Japan. Since 1990s, the research work on this kind of bridge has begun in our country, and the first PC composite box-girder bridge with corrugated steel webs was built in 2005.At present, many studies on the PC composite box-girder bridge with corrugated steel webs, in domestic and abroad, are mainly concentrated on shear bucking mode of the web, characteristics of bending and torsion, bearing capacity of normal section, etc. There are still few researches on construction technique and structural parameter. On the basis of summary and analysis of the research result about flexural behavior and shear bucking mode, relating to the new structure in domestic and abroad, this thesis makes researches including two points as fallows: one is the analysis of the mechanical behavior and deformation of the long span PC composite continuous box-girder bridge with corrugated steel webs in process of construction; another is the study on the influence of the prestressing parameters to the bridge, such as sequence of prestressed stretching construction, ratio of the external prestressing force and layout of external tendons.The research which this thesis makes, show that it's feasible using cantilever construction technique to build long span PC composite continuous box-girder bridge with corrugated steel webs and the shear stress of the corrugated steel web is not control items during construction stages. Using the same construction technique, the creep secondary internal force is different when external tendons of side span are stretched in different stages. The structure's mechanical performance could be improved by changing the parameters of the external prestressing system such as sequence of prestressing stretching construction, ratio of the external prestressing force and layout of external tendons.