集中荷载和均布荷载作用下悬臂箱梁剪力滞效应试验

Test on Shear Lag Effect of Cantilever Box Girder Under Concentrated Load and Uniformly Distributed Load

对悬臂箱梁进行集中荷载和均布荷载的加载试验,探讨沿箱梁轴向剪力滞影响程度的变化,以及加载形式对悬臂箱梁不同区域的剪力滞影响.结果表明:在集中荷载和均布荷载作用下,悬臂箱梁同时存在正剪力滞现象和负剪力滞现象,从自由端至固定端方向,箱梁受负剪力滞的影响逐渐减小,受正剪力滞的影响逐渐增大;均布荷载作用下的剪力滞系数大于初等梁理论的计算值;相较于均布荷载,悬臂箱梁在集中荷载作用下受剪力滞的影响较小,正、负剪力滞分界点离固定端较远.

The cantilever box girder is tested under concentrated load and uniformly distributed load.The influence of the shear lag along the axial direction of the box girder and the influence of the loading form on the shear lag of different regions of the cantilever box girder are discussed.The result shows that under concentrated load and uniformly distributed load,there are both positive and negative shear lag phenomenons in cantilever box girder.From the free end to the fixed end,the influence of negative shear lag on box girder decreases gradually,and the influence of positive shear lag increases gradually.The shear lag coefficient under the uniformly distributed load is greater than the calculation value of the elementary beam theory.Compared with the uniformly distributed load,the cantilever box girder is less affected by the shear lag under the concentrated load,the demarcation point of positive and negative shear lag is far from the fixed end.