绵阳涪江三桥病害处置与系杆更换实施方案研究

发布时间：2018-12-17 01:10

【摘要】：20世纪90年代以来,系杆拱桥在国内快速发展和广泛应用。早期修建的系杆拱桥多采用永久系杆,研究表明系杆在简易防腐措施和高应力等因素影响下仅有20～30年使用寿命,现行规范明确为20年。随着系杆病害恶化和使用年限的到达,需将原系杆更换为可更换的系杆。以绵阳涪江三桥为工程背景,对其病害处置措施和系杆更换实施方案进行研究:(1)基于涪江三桥病害发展历程与维修历史,总结了病害成因,提出了更换全桥系杆、吊杆锚头排水与防腐处理、主拱肋二次灌浆、更换桥面板及新增钢纵梁等病害处置措施。(2)结合涪江三桥的受力特点和系杆构造,提出新增系杆方案和等荷置换系杆方案,通过定性分析和有限元计算进行方案比选;新增系杆不利于边跨受力,且新锚固段和原结构的联结难以保障;等荷置换系杆按单根系杆置换荷载,结构变形和内力变幅小,更换前后结构受力、外观保持一致,将等荷置换方案作为系杆更换方案。(3)对等荷置换系杆的实施方案进行了研究,完成了主要构件和施工流程的设计;通过对整个更换过程共61个施工阶段的有限元分析,得到等荷置换系杆过程主跨的位移、应力变幅小,结构安全,拱顶截面位移最为敏感,提出了以拱肋位移的控制指标;提出了实施过程中边跨临时支撑体系、边拱肋保护性拆除、带应力断索和浇筑混凝土等环节的质量控制措施。等荷置换系杆对涪江三桥的系杆更换施工图设计和现场施工具有指导意义,同时为其它系杆拱桥系杆加固或更换提供参考和借鉴。
[Abstract]:Since the 1990's, tied arch bridges have developed rapidly and been widely used in China. In the early construction of tied arch bridge, permanent tie is used. The research shows that the service life of tie bar is only 20 ~ 30 years under the influence of simple anticorrosion measures and high stress, and the current code is 20 years. With the deterioration of tie-rod disease and the arrival of service life, the original tie rod should be replaced with replaceable tie bar. Based on the engineering background of Fujiang No.3 Bridge in Mianyang, the measures to deal with the disease and the scheme to replace the tie rod are studied. (1) based on the development history and maintenance history of the disease in Fujiang third Bridge, the causes of the disease are summarized, and the replacement of the tie rod of the whole bridge is put forward. Drainage and anticorrosion treatment of suspender anchor head, secondary grouting of main arch rib, replacement of bridge deck and new steel longitudinal beam, etc. (2) combined with the mechanical characteristics and tie bar structure of Fujiang No. 3 Bridge, the new tie bar scheme and the equal charge replacement tie bar scheme are put forward. Through qualitative analysis and finite element calculation, the scheme is compared and selected; The new tie bar is unfavorable to the side span force, and the connection between the new anchoring section and the original structure is difficult to guarantee. The displacement load of the equal-load replacement tie bar according to a single tie bar, the deformation of the structure and the internal force change are small, the force of the structure before and after the replacement is changed, and the appearance of the tie bar remains the same. The equal-load replacement scheme is used as the replacement scheme. (3) the implementation scheme of peer-to-peer replacement is studied and the design of main components and construction flow is completed. Through the finite element analysis of 61 construction stages in the whole replacement process, the displacement of the main span in the process of equal load replacement tie bar is obtained, the stress amplitude is small, the structure is safe, and the displacement of the arch section is the most sensitive. The control index of the displacement of the arch rib is put forward. The quality control measures of temporary bracing system with side span, protective removal of arch rib, stress broken cable and pouring concrete are put forward. The equal-load replacement tie bar is of guiding significance to the design of the tie-bar replacement drawing and site construction of Fujiang No. 3 Bridge, and also provides a reference for the reinforcement or replacement of the tie bar of other tied arch bridges.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U445.7

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