Applied Calculation Of Shear Lag Effect Of Wide Box Girder Bridge

With the development of economic,our country’s increasing traffic flow,the width of thebridges is also increasing，so the form of cross section of box girder changes from box girderwith single-box single-chamber to box girder with single-box multi-cell，that is more andmore wide box girder bridge will be used in the bridge construction. Most study of the shearlag effect focus on box girder with single-box single-chamber at present，but the study of theshear lag effect of wide box girder is very few. Yet our current specifications lack how todetermine the shear lag effect of wide box girder bridge，therefore，it is necessary to study theshear lag effect of wide box girder bridge.This article systematically introduced the current research of shear lag effect ondevelopment and its theory，and then put forward the research content and direction of myarticle according to the current research status. Analyzed the shear lag effect of box girderwith single-box four-room with analogous bar method，obtained the calculation formula ofshear lag coefficient of simply supported and cantilever beam under concentrated anddistributed load. Deduced the differential equation of shear lag effect of box girder withsingle-box four-room based on the energy variational method，solved the energy variationalmethod according to the boundary conditions of common and typical structure forms.Calculation results from finite element software ANSYS and MIDAS at engineering examplewas Combined with analogous bar method and energy variational method，and prove thederived formula is correct after comparison demonstrated. Introduced four appliedcalculations of shear lag effect of wide box girder bridge and its limitations，Then accordingto the laws of shear lag effect of wide box girder bridge and the energy variational methodformula，Put forward the corresponding fitting function and fitting calculated data withOrigin，obtained the applied calculation formula of cantilever plate and wing of wide boxgirder bridge of simply supported under concentrated and distributed load. This is the firsttime to fit applied calculation of shear lag combined with the Origin software and the methodof probability，provided the bridge engineering design personnel with reference calculation ofshear lag of wide box girder bridge.