大跨度异形拱桥全桥受力行为及稳定性分析

Analysis of the Full-bridge Mechanical Behavior and Stability of Long-span Special-shaped Arch Bridge

为了研究大跨度异形拱桥全桥的整体受力及稳定性,通过有限元分析软件Midas Civil设置不同的工况对全桥的受力特性和稳定性进行分析。研究结果表明:主要承重构件梁和拱的最大弯曲应力出现在承载能力极限状态下的工况中,吊杆应力最大值多出现在靠近拱脚处的吊杆之中;活载作用对主梁与拱肋部位的下挠值起控制作用;稳定性分析表明,全桥结构的第1阶模态失稳特征值为10.9,失稳模态为面外反对称失稳,大桥的稳定性较好。

To study the overall mechanical behavior and stability of the long-span special-shaped arch bridge, Midas Civil was used to set different cases to analyze the mechanical characteristics and stability of the bridge. The research results show that the maximum bending stress of the main girders and arches appears in the case under the ultimate limit state,and the maximum stress of suspenders mostly occurs in suspenders near the arch springing;the live load plays a crucial role on the deflection value of the main girder and the arch rib;the first-order modal instability characteristic value of the bridge is 10.9 and the instability mode is out-of-plane antisymmetric instability,so the bridge has good stability.