【作者】 张坤；

【导师】 雷俊卿；

【作者基本信息】 北京交通大学 ， 桥梁与隧道工程， 2014， 博士

【摘要】 随着桥梁设计理论的进步、施工技术的提高,人们对于桥梁设计的要求,不再仅仅是从安全与适用的角度,而是从桥梁美学的角度提出更高的期望,叠合拱桥因跨越能力强、刚度大、造型美观、桥下净空较大等特点,在高速铁路桥梁得以应用。叠合拱桥是一种将组成主拱肋的上、下拱肋部分分离,且拱脚分设在不同墩台上或同一墩台上的拱桥体系。本文在总结国内外大跨度钢拱桥发展与研究成果的基础上,以哈大高速铁路新开河桥为工程背景,对高速铁路钢箱叠合拱桥结构的设计、实桥试验以及吊杆锈蚀损伤的结构安全评估等关键问题进行了系统的研究。首先,对新型的叠合拱桥结构体系的梁拱协作机理与简化实用计算进行了研究。通过对均布荷载作用下叠合拱桥结构连接杆与吊杆的有限元分析结果进行归纳分析,做出吊杆内力大小相等、连接杆内力大小相等的假定,将吊杆与连接杆内力假定为膜张力,将叠合拱桥结构分为梁拱组合体、吊杆与连接杆三种构件,基于变形协调方程,求解出了均布荷载作用下叠合拱桥结构体系的吊杆与连接杆均布膜张力以及拱肋与主梁挠度的简化公式,并对公式进行误差分析与修正。其次,针对高速铁路钢箱叠合拱桥结构体系进行了全面的研究。以哈大新开河桥为工程背景,采用有限元数值方法系统地研究了高速铁路钢箱叠合拱桥结构动静力力学行为与稳定性能。分析了矢跨比、拱肋内倾角、横撑布置形式、吊杆布置形式与拱肋系梁刚度比等结构设计参数对钢箱叠合拱桥结构力学行为的影响。考虑设计中对于梁端转角的验算,基于改善的响应面法,对高速铁路钢箱叠合拱桥梁端转角进行了可靠性评估。再次,基于哈大高速铁路新开河桥的实桥试验,对高速铁路钢箱叠合拱桥施工阶段进行计算分析,结合倒拆分析法,分析吊杆的施工阶段的内力,保证最终的成桥状态满足设计要求。由于对主桥的全面有效的实桥测试,不仅保证施工的安全,更得到大量很有价值的数据,为进一步分析和研究创造了有利条件。最后,计算分析了吊杆损伤对高速铁路钢箱叠合拱桥结构动静力力学行为与稳定性能的影响。基于区间概率可靠度分析理论,建立锈蚀损伤钢构件失效模式的分析模型,计算分析该构件各失效模式的区间失效概率,证明了区间概率在钢结构的锈蚀损伤安全评估中的适用性。基于吊杆锈蚀损伤的模型,计算分析了新开河桥在运营阶段的结构安全性能。通过本文的研究,对高速铁路钢箱叠合拱桥结构体系、结构形式、简化计算、实桥试验、吊杆损伤的结构安全评估等方面进行了较为系统的分析研究,为叠合拱桥的设计、施工与运营阶段结构的安全评估提供依据和参考。更多还原

【Abstract】 With the continuous development of the design theory and the construction technology of bridge engineering, safety and applicability are not the only main factors to consider in design, and the aesthetic quality of the bridge becomes active demand of times. Possessing the advantages of strong span ability, high stiffness, attractive appearance, big clearance under bridge and so on, stacked arch bridge has been applied in high-speed railway bridges. Stacked arch bridge is a new arch system, in which parts of the arch rib is separated into upper and lower arch rib and their skewbacks are fixed on a same pier or different piers. In this paper, the domestic and foreign development and research results of long-span steel arch bridges are summarized, and based on Xinkai River Bridge on Harbin-Dalian high-speed railway, systematic study of the structure of high-speed railway steel-box stacked arch bridge is made, including mechanical performance, experimental test, and safety assessment of corrosion-damaged suspenders. The main work and conclusions are as follows:Firstly, cooperation mechanism between beam and arch ribs of the new stacked arch bridge structure system and its simplified calculating method are studied. After inductive analysis of FEA result of suspenders and connection rods of stacked arch bridge under uniform distributed loads, internal forces of suspenders and connection rods are assumed to be respectively equal and treated as membrane tensions, and stacked arch bridge structure is divided into beam-arch, suspenders and connection rods. Based on the deformation coordination equation, the expressions of membrane tensions and the deflection of beam are solved.Secondly, the complete study of the structure of high-speed railway steel-box stacked arch bridge is carried out. Taken Xinkai River Bridge on Harbin-Dalian high-speed railway as case study, mechanics behavior of static and dynamic force and stability performance of steel-box stacked arch bridge are calculated, and effects of structure design parameters on structure mechanical behavior is analyzed, such as rise-span ratio, leaning angle of arch rib, layout of crossbars, layout of suspenders and rigidity ratio of arch rib to beam. Based on the improved response surface method, the reliability of rotation angle at beam end of high-speed railway steel-box stacked arch bridge is assessed.Thirdly, combining with experimental test of Xinkai River Bridge, structure of high-speed railway steel-box stacked arch bridge under each construction stage is calculated. Optimal control tension of suspenders and internal force and displacements of arch bridges is analyzed to meet the design requirements by adopting the backward analysis method which improves the construction control precision. Due to the experimental test for construction stages, the safety of the construction is ensured and favorable conditions for further analysis and research is created.Finally, effects of corrosion-damaged suspenders on the static and dynamic mechanical behavior and stability are analyzed. Based on the interval reliability theory, different corrosion-damaged failure modes are established to analyze the interval reliability of the steel component, which indicates that the reliability analysis of corrosion-damaged steel structure based on interval reliability theory is more objective and comprehensive in the safety assessment of existing steel structures. The structure safety performance of Xinkai River Bridge in operation stage is calculated and analyzed based on the corrosion-damaged suspender model.The structure system, structural parameters, simplified calculation, experimental test and structural safety assessment of corrosion-damaged suspender of high-speed railway steel-box stacked arch bridge are systematically analyzed and researched in this paper, which would provide the basis and reference for the design, construction and operation stages of stacked arch bridge.更多还原