钢管混凝土桁架系杆拱桥稳定性分析

Stability Analysis of Concrete-Filled Steel Tubular Truss Tied Arch Bridge

以钢管混凝土桁架拱肋的系杆拱桥为研究对象,拱肋的组合刚度以组合柱为计算模型,考虑拱肋面内以三角形桁架为组合件,经过布置优化,得到相应的组合效应系数后,以拱梁共同作用确定面内临界轴压力。对面外稳定性,以k式桁架为纵向联接系确定临界轴压力。对于四管组合的独榀拱肋布置,考虑吊杆力偏移的非保向力效应,对拱提供抗失稳的扶正力作用。通过算例,以主跨lp=120 m的钢管混凝土桁架拱肋的系杆拱桥的稳定性验算的全过程,展示了所介绍方法的实用性。

The paper takes the tied arch bridge of steel tube truss arch rib as the research object.The combined stiffness of the arch rib is calculated by the combined column.Considering the triangular truss as the assembly in the rib surface,after the layout optimization,the corresponding combined effect coefficient is obtained,and the critical axis force of in-plane stability is determined by the interaction between arches and beams.For out-of-plane stability,the critical axis force is determined by the k-type truss as the longitudinal joint system.For the four-tube combination of the single arch rib arrangement,considering the non-directiona load effect of the suspender tensile force offset,this arrangement provides the arch with the uprighting force to enhance the stability.Through an example,the practicality of the method described in this paper is demonstrated by the whole process of checking the stability of the concrete-filled steel tubular truss tied arch bridge with a main span of 120 m.