EFFECTIVE WIDTH OF MAIN GIRDER WITH SEPARATED DOUBLE-RIB CROSS SECTION UNDER AXIAL PRESSURE

摘要

Effective width of main girder with separated doublerib cross section under axial pressure to width of deck slab is clearly defined,which is called ratio of effective width. The formula is derived in the paper. By adopting the displacement pattern of shear lag warping for n-order parabola and based on energyvariational principle,equilibrium differential equation of main girder with separated double-rib cross section under axial pressure considering the shear lag effect is established. Then,solution of the differential equation,the formula of stress and effective width on any point in cross section are derived. Accuracy of the theory and formula are verified also by the model,and influence of such structure parameters as width-span ratio and surface ratio are comprehensively discussed. Lastly,practical table for calculating effective width ratio is worked out,which can be used as reference for initial design. The formula and table can be conveniently applied to calculate effective width of main girder with separated double-rib cross section under axial pressure.