夜郎湖大桥主拱构造及其力学行为研究

发布时间：2018-10-12 08:54

【摘要】：大跨径拱桥的发展与施工技术的进步密不可分。拱桥以受压为主,将抗拉强度低、抗压强度高的混凝土材料应用在拱结构中是为之合理的。但随着跨径增大,施工难度显著增大。国外大跨径钢筋混凝土拱桥大多采用悬臂浇筑法或悬臂浇筑与劲性骨架组合法进行施工,相比于国外,国内无论在施工经验还是理论方面仍存在差距。本文依托贵州省交通运输厅科技项目“悬臂浇筑与劲性骨架组合的大跨度砼拱桥技术关键与示范”的子项目“单箱单室主拱圈构造与受力行为研究”,针对贵州夜郎湖大桥主拱圈采用的单箱单室截面形式,主要开展以下工作：①基于弹性薄板理论和拱的等效压杆理论,开展悬臂浇筑和劲性骨架组合施工主拱圈截面形式与构造研究；推导了主拱圈强度破坏、整体失稳与拱圈局部屈曲临界状态下板厚计算公式,依据拱圈厚宽比(ζ=t/b)可确定拱圈在三种临界状态下的先后破坏顺序。②开展了拱圈单箱单室、单箱双室、单箱三室三种截面形式的研究,结果表明单箱单室截面具有很强的抗侧倾能力,减少箱室个数对拱圈顶底板临界厚度影响显著；设置顶底板翼缘可以减少局部屈曲状态的临界厚度。③运用数值分析方法,研究劲性骨架构造与长度对主拱圈刚度的影响规律；采用能量方法推导了主拱含劲性骨架截面的等效刚度。研究表明,当劲性骨架长度为主拱圈跨径的1/2左右时主拱等效刚度分布最为平顺；用等效刚度原则分析含劲性骨架的组合截面刚度效应,结果表明劲性骨架构造对成桥状态主拱内力、变形、动力、稳定性能影响不明显。④针对设计所采用的劲性骨架构造,开展了施工阶段的稳定分析,研究了温度对施工过程的影响。
[Abstract]:The development of long-span arch bridge is closely related to the progress of construction technology. Arch bridge is mainly under compression. It is reasonable to apply concrete material with low tensile strength and high compressive strength to arch structure. However, with the increase of span, the construction difficulty increases significantly. Long span reinforced concrete arch bridges abroad are mostly constructed by cantilever pouring method or cantilever pouring and stiffening skeleton combination method. Compared with foreign countries, there is still a gap in construction experience and theory in our country. This paper relies on the technology key and demonstration of long-span concrete arch bridge combined with cantilever construction and rigid skeleton, which is a sub-project of Guizhou Provincial Transportation Department, "study on the structure and stress behavior of main Arch Ring with single Box and single Chamber". In view of the single box and single chamber section of the main arch ring of Youlang Lake Bridge in Guizhou, the following works are carried out: 1 based on the theory of elastic thin plate and the equivalent pressure bar theory of arch, The section form and structure of main arch ring in cantilever pouring and rigid skeleton combination construction are studied, and the calculation formula of plate thickness under the critical state of main arch ring strength failure, global instability and local buckling of arch ring is derived. According to the thickness to width ratio of arch ring (味 = t / b), the failure sequence of arch ring in three critical states can be determined. The results show that the section of a single box has a strong anti-roll ability, and reducing the number of the box room has a significant effect on the critical thickness of the arch ring roof and bottom plate, and setting the flange of the top and bottom plate can reduce the critical thickness of the local buckling state. The influence of the structure and length of rigid skeleton on the stiffness of the main arch ring is studied, and the equivalent stiffness of the section of the rigid skeleton of the main arch is derived by using the energy method. The results show that the equivalent stiffness distribution of the arch is the most smooth when the span of arch ring is about 1 / 2 of the stiffness skeleton length, and the stiffness effect of the composite section is analyzed by using the principle of equivalent stiffness. The results show that the stiffness skeleton structure has no obvious influence on the internal force, deformation, dynamic and stability performance of the main arch in the state of the bridge. 4 according to the stiffness skeleton structure adopted in the design, the stability analysis of the construction stage is carried out. The influence of temperature on construction process is studied.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.4

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