Research On Local Structure Of Separate Orthotropic Deck Flat Steel Box Girder

In the past 20 years, with the rapid development of long-span bridge, orthotropic deck flat steel box girder of the new types of long-span bridges is widely applied thanks to its small dead weight, large capacity of spanning in both length and breadth directions, time sparing in both factory and site work, no creeping in girder and good vibration adopting capacity so on. The beam which was slotted at the bridge beam axis to satisfy the requirements of wind-resistant stability in the long-span suspension bridge and cable-stayed bridge is separate steel box girder. Orthotropic deck flat steel box girder has the characteristics of both orthotropic deck and box girder, but it is not fully mature and a series of issue about design, manufacture, installation. People are not reached unity and maturity about its understanding.In this thesis, the steel box girder of Jiashao Bridge is taken as a numerical example. And the local structure of steel box girder is systematically studied on the basis of researcher achievements and design specifications home and abroad. The main contents of this thesis are described as follows:1. The history of the development, the present situation of the art in bridge engineering and the technical problems of orthotropic deck flat steel box girder is recounted.2. During the construction stage, lifting segment, the transverse deflection of segment to be lifting is opposite of segment supporting crane, the connection section of these two segment will occur to some extent deformation difference, thus the problem is produced during segment connection. Calculating about this is done in the thesis.3. Selecting two groups of top plates' arrangement conditions, the thickNess and height of the U rib are different, which including original design, calculation and analysis the stress and deflection of them under the effect of vehicle load.4. Selecting different arrangement conditions of transverse diaphragm's distance, which including original design, calculation and analysis the distribution situation of the bending normal stress and warping stress under the effect of eccentric load.Through the above analysis, the stress and deflection of the stiffened plates and U rib of the steel box girder is obtained. I hope the researchment in this thesis can provide reference for orthotropic deck flat steel box girder of long-span bridges design and construction.