部分充填混凝土窄幅钢箱组合梁抗弯承载力

Bending capacity of concrete-partially-filled narrow-width steel box composite beams

为了研究部分充填混凝土窄幅钢箱连续组合梁负弯矩区抗弯承载力,完成了3根简支组合梁在负弯矩作用下的弯曲性能试验;分析了影响部分填充混凝土窄幅钢箱连续组合梁负弯矩区结构受力性能的主要因素。通过换算截面原理以及混凝土翼板参与受拉的程度系数m来确定组合梁截面惯性矩与抗弯刚度,推出部分充填混凝土窄幅钢箱连续组合梁负弯矩区的弹性抗弯承载力计算公式;基于简化的塑性理论,得到负弯矩区极限抗弯承载力计算方法,并进行计算值和实测值对比分析。总体而言,充填的混凝土限制了受压部位钢箱的结构变形,能够明显提高钢箱组合梁负弯矩区的弹性工作范围和极限承载力,使钢箱组合梁具有更好的工作性能。

In order to study the bending capacity of negative moment regions of concrete-partiallyfilled narrow-width steel box composite beams,flexure test on 3 beam specimens under negative moments were carried out,and the main factors that affected the mechanical properties of negative moment regions of concrete partially-filled narrow-width steel box composite beams were analyzed.Based on the sectional transforming principle and the coefficient m,the inertia moment of cross section and flexural rigidity for the composite beams can be determined,and the formula to calculate the elastic flexural bearing capacity of negative moment regions were deduced.Besides,the ultimate flexural bearing capacity of negative moment regions was obtained from the simplified plasticity theory,and the calculated results are generally in good agreement with the test results.