【作者】 任晓强；

【导师】 贾艳敏；

【作者基本信息】 东北林业大学 ， 道路与铁道工程， 2004， 硕士

【摘要】 在公路与城市桥梁中，拱桥以其跨越能力大、承载能力高、工程造价低、养护维修费用少、桥型宏伟壮观等特有的优势而成为建筑历史最悠久、数量最多、竞争力最强、并且长盛不衰、不断发展的桥梁结构型式。拱肋作为压弯结构，随着跨径的增大，杆件的长细比及所承受的荷载也随之增大，拱圈横向刚度、宽跨比相对减小，在施工阶段及使用阶段横向稳定问题特别突出，常常成为拱桥设计的控制因素。因此，拱桥的整体稳定性就成为愈来愈突出的问题。 本文以大跨度悬链线单肋无铰拱桥为对象，在总结前人对圆弧、抛物线肋拱横向稳定实用简化计算和有限元分析的研究成果的基础上，对上承式、中承式和下承式的大跨度悬链线单肋无铰拱桥的横向静风稳定问题进行了系统的分析研究。 1．本文通过对承受竖向均布荷载和横向风荷载的悬链线单肋无铰拱的分析，利用能量原理，建立了单肋拱的横向静风稳定屈曲临界荷载的计算公式。分析了拱肋的抗扭刚度与横向抗弯刚度比、拱轴系数、矢跨比、桥面系的横向抗弯刚度与拱肋的横向抗弯刚度比、桥面系横向刚度引起的非保向力效应、横向风荷载对单肋拱横向稳定的影响，并给出了相应的图表，为拱桥设计时拱肋的结构参数的选取提供一定的依据。 2．本文利用大型综合有限元程序ANSYS，以已建的依兰牡丹江中承式钢管混凝土拱桥为例，考虑几何非线性和材料非线性效应，用增量和Newton Raphson迭代法详细分析大跨度钢管混凝土拱桥在不同加载方式作用下的稳定极限承载力。讨论了不同加载方式对大跨度钢管混凝土拱桥极限承载力的影响。更多还原

【Abstract】 In urban and highway bridges, the CFST arch bridge is the bridge construction style with large amount, strong competition, long history, activity and ever development because of its large span, high capacity, low cost and maintenance fees, grand figuration and etc. As a compress-bend structure, with increasing of the span, length slender ratio and carrying load of arch increase, lateral rigidity and width span ratio of arch ring minish relatively. During construction and service stages, lateral stability becomes more important and a control factor of arch bridge design. So lateral ultimate loading capacity of CFST arch bridges is becoming a more and more serious problem.Based on the summary of current researches on circularity and parabola arch at home and abroad, taking the long-span catenary arch bridge without cross-beam as the object of study, a practical method for the lateral stability calculation of ribbed arches with catenary rib curve is established. Lateral ultimate loading capacity of long span catenary arch bridge(deck bridge, half-through bridge, through bridge) was analyzed systemly.1. Catenary single rib arch that carries vertical loadings and transverse wind loadings was analyzed in this paper, calculation formula of critical loading of lateral stability flexuosity by the energy principle. The structure parameter influences on lateral stability, such as crankle rigidity ratio of arch rib, arch axis coefficient, arch high span ratio, lateral rigidity of bridge decking and arch rib ratio, the effect of non-orientedly conservative loadings of bridge deck, lateral wind loadings were discussed. Corresponding numerical charts were given, and they may be of some reference value and helpful to the parameter design of ribbed arches.2. In this paper, the example bridge is a long-span half-through CFST arch bridge of a 100m span in Yi Lan. Two loading sequences are used to determine the load-deformation response and the ultimate load of the bridge: Sequence I is the sequence in which the dead and wind loads are applied first and then the live load is increased proportionally to the collapsed load ; Sequence II is the sequence in which the dead and live loads are applied first and then the wind load(wind velocity) is increased proportionally to the collapsed load(critical wind velocity). The ultimate capacity of this bridge under two loading sequences is investigated using geometrically and materially nonlinear buckling method. The effects of long-span CFST arch bridges are discussed.更多还原