大跨度两铰钢拱桥面内结构设计计算方法

大跨度拱桥具有显著的几何非线性力学行为,按线性设计理论不能满足安全要求,考虑由拱肋变形产生的附加弯矩和精确推算结构的稳定强度是设计中的重要课题。以两铰钢拱桥为对象,提出了考虑非线性影响以及高精度稳定强度的拱桥结构设计方法,以跨度160 m和200 m的两桥计算模型为例,验证了按非线性理论设计的必要性以及本设计方法的合理性,分析结果表明按线性计算方法和弹性稳定理论不能精确评价结构的受力特性和强度。

A STRUCTURAL DESIGN AND ANALYSIS APPROACH OF TWO-HINGED LONG-SPAN STEEL ARCH BRIDGES UNDER IN-PLANE LOADING

Because of the notable geometrical nonlinear behavior, the safety requirement of long-span arch bridge structures cannot be met by using linear analysis theory. It is of significance problem to study the additional bending moment induced by the deformation of rib arches and the stability of the arch bridge structures. This paper proposes a structural design and analysis approach of two-hinged long-span steel bridges under in-plane loading. Effects of geometrical nonlineariety and stability in high precision are considered and two arch bridge model calculations with spans 160m and 200m, respectively, are provided. The necessity of the nonlinear theory as well as the rationality of the proposed approach is examined. From the numerical results, it is found that geometrical nonlineariety is an important factor in the design of two-hinged long-span steel arch bridges, and that linear analysis method and elastic stability theory cannot precisely evaluate the ultimate strength and instability behavior of arch bridges.