The Shear Lag Effect Research Of Separated Steel Box Girder In Big Span Cable-stayed Bridge

Because of advantages of small Structure self-weight and good mechanical behavior,Separated steel box girder are used more and more extensive application in large-span cable-stayed bridge.Compared with traditional single box steel box girder, separated steel box girder has reduced the self-weight of beam, but the shear lag effect is relatively more apparent. We want to further reseach the shear lag effect of the cable-stayed bridge’s separated steel box girde. So we based on the research results of the girder in the past, aim at the construction process and bridge operation condition of cable-stayed bridge to systematically analyse the shear lag effect of separated steel box girder, The main research contents are as follows:1、Using spatial plate and shell finite element set up multi-level three-dimensional analytical mode of the separated steel box girder through an parameters influence analysis of main girder shear lag effect under dead weight load, cable forces, bridge deck crane load and temperature load to get different regular pattern of shear lag effect when it under different load.2、Aim at the typical working conditions (the biggest single girder cantilever, the biggest double cantilever and the second beam assembled completely) in construction process of separated steel box girder cable-stayed bridge, through analysis research the shear lag effect of separated steel box girder which in typical stress state,get the shear lag coefficient regularity of distribution along the cross section of the steel box girder and bridge spans the longitudinal under different construction step.3、Aim at bridge in the state and live load loading condition of separated steel box girder cable-stayed bridge reseached the shear lag effect of girders to get the shear lag coefficient regularity of distribution along the cross section of the steel box girder and bridge spans the longitudinal under bridge in the state and live load loading condition.4、Aim at the static load test of loading condition of the specific force state, analyse the distribution of shear lag coefficient, through compare the shear lag coefficient which get from the measured data to be inferred, it assessed that using multi level three-dimensional analytical mode in this text to analyse the shear lag effect is reliable.