%0 Journal Article %T 新月型钢管混凝土拱桥极限承载能力分析<br>Analysis of Ultimate Load-Carrying Capacity of Crescent-Shaped Concrete-Filled Steel Tube Arch Bridge %A 马明 %A 钱永久 %A 徐佰顺< %A br> %A MA Ming %A QIAN Yongjiu %A XU Baishun %J 西南交通大学学报 %D 2017 %R 10.3969/j.issn.0258-2724.2017.04.005 %X 为了研究结构参数对新月型钢管混凝土拱桥极限承载力的影响，基于考虑约束效应的核心混凝土本构关系，对新月型拱桥的极值点稳定问题进行了分析.首先通过特征值分析，获取对结构承载能力最不利的荷载工况；其次在该工况下考虑结构的几何非线性和材料非线性，采用Riks法迭代求解，得到结构的极限承载力和稳定安全系数；最后以石棉大渡河桥为工程背景，研究了主副拱肋夹角、钢管材料强度、核心混凝土强度、含钢率等结构参数对极限承载能力的影响.研究结果表明：新月拱的失稳形式为拱肋整体的横向失稳，结构的稳定性主要取决于恒载大小；考虑几何非线性后，极限承载能力下降3%，当初始缺陷从1%增加至10%时，极限承载能力下降1%，考虑材料非线性后，承载能力下降55%；含钢率增加至1.5倍时，稳定安全系数提高19.0%；核心混凝土强度从C50提高至C60时，稳定安全系数提高12.0%；钢材强度从Q345提高至Q420时，稳定安全系数提高9.6%；随主副拱肋夹角从10°变化至25°时，稳定安全系数降低5.9%.<br>： In order to investigate the influences of structure parameters on the ultimate load-carrying capacity of crescent-shaped concrete-filled steel tube arch bridge, based on the constitutive relation of core concrete under confinement, the extreme-point stability of the arch bridge was analyzed. First, the most unfavorable load combination for ultimate load-carrying capacity was obtained by eigenvalue analysis, and then by considering the effects of the geometry nonlinearity and material nonlinearity in this loading condition, the ultimate load-carrying capacity and safety factor of stability were solved by Riks iterative solution. At last, the Shimian Dadu River Bridge was used as an example to analyze the effects of structure parameters on ultimate load-carrying capacity such as the angle between main and side arch rib, the strengths of steel and core concrete, and steel ratio. The analysis shows that the buckling mode of the crescent-shaped arch bridge is transverse deformation of the whole rib, and the structure stability mainly depends on the sustained load. The bearing capacity decreased 3% when considering geometry nonlinearity, decreased 1% when the initial imperfection increased from 1% to 10%, and decreased 55% when considering both geometry and material nonlinearities. When the steel ratio is increased by 50%, the safety factor of stability increased 19.0%; with the concrete strength increasing from C50 to C60, it increased 12.0%; with the steel strength increasing from Q345 to Q420, it increased 9.6%; with the angle between ribs increasing from 10°to 25°, it decreased 5.9% %K 新月型拱桥 %K 极限承载能力 %K 稳定 %K 非线性 %K 本构关系 %K 含钢率 %K < %K br> %K crescent-shaped arch bridge %K ultimate load-carrying capacity %K stability %K nonlinearity %K constitutive relation %K steel ratio %U http://manu19.magtech.com.cn/Jweb_xnjd/CN/abstract/abstract12455.shtml