The Design And Calculation Of Jinghang Cannel Bridge And Research On Provisional Anchor

Jinghang Cannel Bridge is a self-anchored suspension bridge with steel box girder in main span and concrete box girder in side span. Using concrete girder in side span has more stiffness. It can anchor the bridge primly, furthermore, the anchor effect make for the decrease of deflection and enhance the whole stiffness. Concrete box girder has more deadweight to counteract the vertical force of main cable. Steel-concrete composite girder suspension bridges can make good use of the mechanical property, so it is economical design scheme. To keep Jinghang canal being open to navigation traffic in the course of construction of this bridge, the concrete girder of side span is first erected, and the next, main cable is anchored temporarily, then segmental steel box girder is hung and fixed one by one.Confirming the final hanger force of the self-anchored suspension bridge is an important content of the structural calculation, and the key of confirming the final hanger force is obtaining the shape of main cable. Considering the different deadweight of the side span and middle span of Jinghang Cannel Bridge, main cable configuration of hybrid beam self-anchored suspension bridge is calculated by means of parabola theory in this paper. According to main cable configuration, the finite model is formed and then hanger force is conformed using the finite element program. The final hanger force is mostly related to deadweight of the girder, and affected by the internal force redistribution caused by prestressing reinforcements, shrinkage and creep of concrete. This paper, collective structural static analysis of Jinghang Cannel Bridge is introduced after the final hanger force is obtained.Anchoring the main cable temporarily and then erecting main beam, this "erecting cable before constructing girder" construction method overcomes the disadvantages of the "constructing girder before erecting cable" construction method of self-anchored suspension bridge. In this paper, three temporary anchoring schemes are discussed based on Jinghang Cannel Bridge, then the difficulty in construction and requirement of materials are contrasted amongst different anchoring schemes. By the analysis and discussion on construction scheme of Jinghang Cannel Bridge, "erecting cable before constructing girder" construction of self-anchored suspension bridge is looked forward to be promoted and expands the application range of self-anchored suspension bridge.