Analysis Of The Long-span Hybrid Cable-stayed Bridge Through Construction Stage

With the rapid development of the bridge technology, hybrid Cable-stayed Bridge displayed strong vitality because of its unique construction and technical characteristics , In recent years, Hybrid Cable-stayed Bridge wide applicated home and abroad, and progressive had been one of the developing direction in long-span bridge. Presently, Edong River Bridge under construction adopted the design scheme of nine span continuous half float dual-tower Hybrid Cable-stayed Bridge, its side span,pier and tower used concrete material, mid-span used steel box girder material, its span attended 926 metres, only less than Angchuanzhou bridge in Hongkong, was the second longest Hybrid Cable-stayed Bridge in the world. Due to its super long-span design, nonlinear problem especially geometrically nonlinear problems stand out in bridge stucture. Meanwhile, concrete shrinkage and creep have non-ignored effect on stucture deformation and internal force along the constuction and operation periods.Based on Edong River Bridge, this paper systemic introduced long-span Cable-stayed Bridge geometrically nonlinear theory, particularly dissertated the maininfluence factor------the sag of inclined cable stays, the interaction of large bendingand axial deformation in bending members: and the large displacements effeets,Addtionally gived the tangent stiffness matrix of space beam-element, which was used by the thesis. Also, the paper introduced relevant concepts and method of concrete shrinkage and creep,cable tension optimization and buckling stability.Cable-stayed Bridge was well known as constructed in stages, the transform of structure system was coMParatively frequent. The rigidity of bridge under construction was commonly lower than its completion state, the influence on structure of geometrically nonlinear could be more significant. Due to the long construction period and unpredictable factors, the changement of scheme in construction will result in that structure actual load case usually not consort with original design, even in conflict with relevant technical specification. In response to the features above on Edong River Bridge, this paper established its three-dimensional spatial finite element model, using the bridge finite element program—Midas, did analysis and research on its whole construction process.