大跨度钢桁架拱桥二阶静风稳定性分析方法研究

摘要

钢桁架拱桥以其优美的结构形式、较强的跨越能力成为城市中跨越大江大河应用最广的桥型之一,其施工中的稳定性问题也是桥梁设计者们关注的焦点之一.根据二阶静风稳定分析的基本理论,阐述了基于通用有限软件ANSYS的二阶静风稳定性的分析方法.并以一座主跨400 m的钢桁架拱桥为例,研究了该桥在施工过程中的二阶静风稳定性问题.分析结果表明:在拱肋合拢前、刚性系杆合拢前和成桥状态3种控制工况下100 a重现期的静风荷载作用时,该桥具有良好的抗风稳定性.通过参数分析得到:在合理范围内,施工荷载和扣索索力变化对结构抗风稳定性的影响有限,而吊杆非保向力对其影响显著.%Steel truss arch bridge with its beautiful structure and large spanning capacity become one of the most widely used type of city bridges across the rivers.however,its safety performance during construction also is the focus of attention for designers.According to the basic theory of the second order aerostatic stability analysis,it described the analysis method of second-order static wind stability based on the finite element software ANSYS.In this paper,with a 400 m main span steel truss arch bridge as background,study the aerostatic stability during construction.The results indicate:before the arch rib dosed,the rigid rod closed and optimum completion state,the safety and stability of the steel truss arch against the wind is fine when 100 years return period wind action.It obtained by parametric analysis within a reasonable range:the impact of construction loads and cable tension to the structure wind resistant stability is limited,but the influence of non-directional loads of hanger rod is significant.