钢-混双组合连续梁抗弯性能研究

Study on Flexural Performance of Steel-Concrete Double Composite Continuous Girder

文章提出一种负弯矩区设置钢管混凝土的工字型截面钢-混凝土双组合连续梁结构形式,并采用有限元方法,分析了该连续梁结构的抗弯性能,结果显示:由于增设了下翼缘钢管混凝土截面,该组合梁结构在负弯矩段的截面抗弯刚度大幅上升,减小组合连续梁负弯矩区上翼缘混凝土板拉应力及开裂,增加了连续梁整体刚度,减小了跨中挠度;腹板的受压边界受到钢管混凝土强有力的约束,腹板承受的弯曲正应力、局压应力大幅下降,腹板高度减小,腹板板件的抗屈曲能力大幅上升;底板受到混凝土的约束,抗屈曲能力亦大幅上升。

This article presented a structure form of setting the CFT I-shaped section steel-concrete double composite continuous girder at negative moment zone,and by using the finite element method,it analyzed the flexural performance of this continuous girder structure,the results showed that：due to the addition of lower flange CFST sections,the sectional flexural stiffness of this composite girder structure sharply rises at negative moment segment,which reduced the tensile stress and crack of upper flange concrete slab of composite continuous girder at negative moment area,increased the overall stiffness of continuous girder,and reduced the deflection between spans;the web compression boundary is under strong CFST constraint,the positive bending stress and local pressure borne by the webs dropped significantly,with the decrease of web height,and the buckling capacity of web plates increased substantially;and under the concrete constraint,the anti-buckling capacity of bottom slab also increased substantially.