斜靠式钢箱系杆拱桥成桥索力检测及稳定性分析

Stability Analysis and Cable Force Detection of Completed Bridge on Slanting Type Tied-arch Bridges with Steel Box Arch Ribs

为研究斜靠式钢箱系杆拱桥(5片拱肋)的稳定性,依托引江济淮工程下承式斜靠拱桥——创新大道桥,对成桥后的斜靠拱桥进行吊杆索力检测;并建立考虑几何及材料非线性的斜靠式钢箱系杆拱桥有限元模型,借助索力检测数据分别与设计索力值和模拟值对比分析,前者评价桥梁吊杆整体张拉控制效果,后者验证斜靠拱桥模型的可靠性;进而对该斜靠式系杆拱桥的稳定性进行了研究。结果表明:实测值与设计值最大误差为3.91%,该斜靠式拱桥吊杆整体张拉控制效果较好;实测值与模拟值最大误差为0.63%,验证了模型的可靠性。其次,施工全过程拱桥结构的稳定系数满足工程要求;斜靠钢箱拱对下承式系杆拱桥稳定性提升程度为72%,斜靠式系杆拱桥的弹性稳定性能高低取决于拱肋面外失稳出现的难易程度,初始几何缺陷对斜靠式系杆拱桥的稳定承载力影响较大;斜靠拱和风撑两者协同工作能显著提高结构稳定承载力。最后给出该类系杆拱桥的设计建议,为同类工程施工和设计提供参考。

In order to study the stability analysis on slanting type tied-arch bridges with steel box arch ribs(five arch ribs),relying on the project of diverting the Huaihe River from the Yangtze River,the through slanting type arch bridge-Chuangxin Avenue Bridge,the suspender cable force detection was carried out on the slanting type arch bridge after completed bridge,a finite element model of the tied-arch bridge on slanting type tied-arch bridges with steel box arch ribs considering the geometric and material nonlinearity was established.The former evaluated the overall tensioning control effect of the bridge suspenders and the latter verified the reliability of the tit over-arch model,then the stability of the tilt-over-arch bridge was studied.The results show that:(1)the maximum error between the measured and designed values is 3.91%,and the overall tensioning control effect of the tilt-over-arch bridge is good.The maximum error between the measured and simulated values is 0.63%,which verifies the reliability of the model;(2)the stability coefficient of the arch bridge structure during the whole construction process meets the engineering requirements,and the slanting type arch bridge with steel box improves the stability by 72%;(3)the elastic stability depends on the difficulty of the out-of-plane instability of arch rib,and the initial geometric defects have a great influence on the stable bearing capacity of the slanting type tied-arch bridge.In addition,the cooperative work of the slanting arch ribs and the wind bracing can significantly improve the stable bearing capacity of the structure;and(4)the design suggestions for this type of tied-arch bridge are given,which can provide a reference for the construction and design of similar projects.