波形钢腹板组合连续箱梁有效翼缘宽度计算初探

针对目前规范中缺少有关波形钢腹板组合连续梁桥有效翼缘宽度的相关规定,提出一种翼缘有效宽度计算方法,以某大跨度波形钢腹板预应力混凝土组合连续箱梁桥为背景,对其有效翼缘宽度计算进行初步研究,研究结果表明:在自重和集中荷载作用下,跨中混凝上内衬边缘的剪力滞效应显著,翼缘板的有效翼缘宽度系数分别达到0.87和0.7左右,其它部位剪力滞效应不明显;而预应力荷载作用下,波形钢腹板组合连续箱梁的各截面处的剪力滞效应均不明显,可以忽略不计,最后通过有限元计算结果与国内外规范对比发现,波形钢腹板箱梁跨中部分有效翼缘宽度与混凝土箱梁基本一致,设计计算时可参照普通混凝土箱梁;内衬边缘截面的剪力滞效应介于普通混凝土箱梁与钢箱梁之间,其有效翼缘宽度的计算也应介于二者之间。

Preliminary discussion on effective flange width calculation of composite continuous box girder with corrugated steel webs

In view of the lack of related provisions on effective flange width calculation of composite continuous box girder with corrugated steel webs in present specifications, the effective flange width calculation is studied by taking a composite continuous box girder with corrugated steel webs as an example. The results show that under the gravity action, only the shear lag effect at the edge of concrete lining is remarkable whose minimum coefficient of flange plate is 0.87, and other parts'' coefficient are 0.95~ 1.05. Under the prestressed load, the shear lag effect of box girder is small, and the effective flange width coefficient is 0.95~1.05. Under the vertical concentrated load, only the shear lag effect at the edge of mid-span concrete lining is most significant, and the shear lag effect gradually increases as the vertical load approaches the mid-span concrete, where minimum effective flange width coefficient is about 0.7, in other parts the effective flange width coefficient is 0.95~1.05.The lengthwise position of the vertical load has no effect on the shear lag effect of side span concrete lining edge and the middle of mid-span. Finally, the comparison study between the FEM results and those calculated based on domestic and international specifications shows that, the effective flange width in the middle of the mid-span of the example bridge is roughly identical to that of the concrete box girder, whose design calculation may be reference to concrete box girder; the shear lag effect at the edge of side span and mid-span concrete lining in the example corrugated steel web girder is larger than that in the concrete box girder but less than that in steel box girder.