桁式索拱桥体系协作机理研究

Research on Structural System Cooperation Mechanism of Truss-Cable Combination Arch Bridge

为研究桁式索拱桥的结构体系机理,提出弹性支承连续梁-桁架-无铰拱的组合体系理论模型;基于各简单体系满足边界位移协调与力的平衡条件,运用柔度法建立理论模型的体系协调矩阵方程组.通过对本文方法、试验实测数据和有限元计算结果的比较,表明所提出的理论模型和分析方法具有较高的精度,可以用来分析桁式索拱桥的体系协作机理;试验模型桥梁的体系协作机理分析结果表明,在满跨均布荷载工况下桁架体系承担大部分外荷载,与普通上承式拱桥力学行为不同.

For understanding structural system cooperation mechanism of truss-cable combination arch bridge, an elastic supported continuous beam-truss-fixed arch cooperative system model was proposed. Based on displacement coordinate condition and force equilibrium condition of simple structural systems in- terface, flexibility matrix equations of structural system cooperation mechanism was deduced. Compared with proposed method results, model test results and finite element method results, it shows that the pro- posed theoretical model and analysis method has high precision; it could be used for structural system coop- eration mechanism analysis of truss-cable combination arch bridges. The results of cooperation mechanism analysis of model test bridge shows that, most external load was born by truss system in uniformly distribu- ted load conditions, and it was a different mechanism from normal deck type arch bridge.