大跨度拱桥稳定性研究

【作者】 林力成；

【导师】 杨炳成；

【作者基本信息】 长安大学 ， 桥梁与隧道工程， 2006， 硕士

【摘要】 拱桥以其跨越能力大、承载力高、空间利用率高、节省材料、造价低和外形流畅美观为特点，成为长盛不衰、不断发展的桥梁形式。随着跨径的增大，刚度越来越柔，作为以受压为主的结构，稳定成为制约其发展的关键因素之一。 我国规范依据已建成桥梁的参数提出拱宽度大于计算跨径的1／20时可不必计算横向稳定性，但宽跨比对稳定的影响程度如何，目前研究较少，本文通过对大跨度拱桥的数值分析，较全面地探讨了宽跨比这一重要设计参数对稳定性的影响，给出宽跨比变化带给稳定性的影响趋势。其次，从变宽度X型肋拱桥稳定性分析出发，给出内倾角度对稳定的影响并特别提出了最优角度。实际拱的失稳大部分属于第二类稳定，二类失稳实际是非线性作用的结果，目前采用的线弹性理论会过高的估计安全系数，本文通过数值分析较精确地给出计入非线性后对稳定计算的影响。最后，结合实际工程，针对具有良好经济适用性的劲性骨架混凝土箱型特大拱桥，进行设计与施工过程稳定性分析，证明其合理性。 本文在国内外研究成果的基础上，针对大跨度拱桥稳定性，依托实际工程，通过有限元算法分析，得出的结论能给相近似的同类桥型设计与施工提供理论指导。更多还原

【Abstract】 Arch bridges constitute a major component in the long-span bridge category because of its high bearing capacity, efficient utilization, saving, low cost and aesthetics. However, arch bridges transmit the applied loads to axial force mainly, which makes arch bridge uniquely susceptible to buckling failure, especially with the slender arch ribs and stiffness decreased.It is said that stability could not be calculated when width-to-span ratio more than 1/20 in JTG code, but the influence appear to be absent in the literature, this study indicate how change buckling safety factor with various width-to-span ratio through numerical analysis of the long-span concrete arch bridges. Furthermore, from the stability analysis of the X-type double ribs arch bridge, this paper show how changes inclined inward angle would affect the stability, and the optimum design is presented. The stability of real arch is the second type that is belong to nonlinear, safety factor will be overrated in linear theory, so nonlinear behavior in calculation is evaluated in this study. Finally, according to the real project, design and construction stability analysis of concrete arch with stiff skeleton of concrete-filled steel tube is investigated, which prove its rationally.Base on the conclusion of study at home and abroad, directed against stability of long-span arch, this study, guided from numerical analysis, provides for theoretical direction to the people engaged in the near type arch bridge engineering after detailed analysis of the design and construction method of the real project.更多还原