美日欧中规范钢桥压杆稳定性计算对比研究

在进行稳定设计时,大部分规范同时考虑构件的整体稳定和板件的局部稳定,不同规范的稳定设计方法差异较大。介绍美国、日本、欧洲、中国四种钢结构桥梁规范中的稳定设计方法,通过将整体稳定折减系数和局部稳定折减系数分别表示为相对长细比和相对宽厚比的函数,绘制4种规范下的稳定折减系数曲线进行对比。同时,针对桥梁工程中常用的翼缘厚度小于40 mm的H形截面杆件,根据各规范中对应的曲线,结合算例计算其稳定折减系数。结果表明:对H形截面受压杆件,整体稳定折减系数为美国规范最大,日本和欧洲规范其次,中国规范最小;局部稳定折减系数为美国和欧洲规范较大,日本和中国规范较小。中国规范在稳定设计方面最为保守。

Comparative Study on Calculation of Stability Capacity of Compression Members of Steel Bridges in AASHTO,JSSC,Eurocode and JTG

The overall stability of components and the local stability of plates are taken into account simultaneously by most codes during stability design,and the methods of the design differ greatly among different codes. Four specifications for steel bridges in AASHTO,JSSC,Eurocode and JTG are illustrated and compared in this paper in terms of stability design. The reduction coefficients of the overall stability and the local stability are respectively expressed as the functions of relative slenderness ratio and relative width to thickness ratio, and the stability coefficient curves are drawn corresponding to the four specifications. For H-shaped section members with a flange thickness less than 40 mm,which are widely used in bridge engineering, the curves under each specification are extracted, and the reduction coefficients of stability are calculated based on cases. The results shown that for the H-shaped section compression member,the overall stability coefficient of AASHTO is the biggest,followed by that of JSSC and Eurocode,while JTG is the smallest. Meanwhile,the local stability coefficients of AASHTO and Eurocode are larger than those of JSSC and JTG. The stable design of JTG is most conservative among the four codes.