Closure Construction&Control Technology Of Steel Truss Girder For Chongqing Qiansimen Jialing River Bridge

Steel-truss-girder cable-stayed bridge is the cooperation system bridge structure combined by traditional cable-stayed bridge and steel-truss-girder bridge, and it is a new bridge type between the said two traditional bridges, and is characterized with both of the bridges but a little closer to an external prestressing continuous girder bridge. This bridge, under the conditions of height limit required by aviation or landscape in city, has an elegant shape of cable-stayed bridge, and enhances the spanning capacity of steel truss girder, and optimizes the structure stress, as well as can be shared by highway and rail, so it is widely used in city bridge construction.This article, using Chongqing Qiansimen Jialing River Bridge as the basic research model, carries out the learning and research on mechanical property&construction technology of steel-truss-girder cable-stayed bridge. This bridge has many difficulties during closure construction such as high stiffness of steel truss girder, many changeable factors of spatial coordinates of closure point, deeply affected by temperature, and high accuracy requirements. In order to successfully complete the construction of this bridge, this article is mainly aimed to solve the following two technical problems.①Carries out the research on the key technology of the closure construction, including the overall construction process of the bridge, analysis of the overall situation of closure and focal&difficult points of construction, comparison and selection of the closure plan of steel truss girder, preparation before closure, basic sequence and specific steps of closure segments installation, sensitivity analysis, adjustment measures, and temporary locking.②Carries out the research on closure control technology, including overall method and content of construction control, closure control goal and simulation analysis, parameter sensitivity analysis, implementation of the closure control and the final control results.The research of this article can not only solve the difficult problems faced by this bridge, but also provide reference for similar bridge construction, and it has a positive meaning to enhance the industry technology level.