考虑剪力滞效应影响的箱梁变形修正计算方法

Modified Calculation Method of Deflection for Box Girders with Consideration of Shear Lag Effect

为了研究考虑剪力滞效应后的箱梁弯曲变形计算问题,由箱梁弯曲的曲率方程出发,探讨了剪力滞效应对箱梁挠曲变形的影响机理。结合设计规范,提出了箱梁弯曲变形计算的剪力滞系数和有效翼缘分布宽度2种修正方法,利用提出的2种修正方法对简支梁和连续梁在集中和均布荷载下的挠度进行了计算。结果表明:剪力滞系数的修正方法精度较高;考虑到设计的方便性,建议在剪力滞系数未知的情况下采用有效翼缘分布宽度修正方法来考虑剪力滞效应对刚度的影响。

In order to study bending deformation and its calculation for box girders considering shear lag effect, mechanism of shear lag effect on bending deformation was investigated based oncurvature equation. Based on the design specification, shear lag coefficient （SLC） and effective flange width （EFW） were presented to modify the bending deflection of box girders. Using SLCand EFW methods, effect of shear lag on deflection of example box girders of simply supported beam and continuous beam under concentrated force and uniform load was analyzed. The resultsshow although SLC has more accuracy than EFW, EFW can be used to calculate box girders deflection when SLC is unknown.