计入病害影响的石砌结构承载力计算方法与应用探索

发布时间：2018-10-26 08:53

【摘要】：本文依托导师承担的国家973计划项目子课题,针对目前缺乏计入风化及纵横向裂缝病害影响的石砌结构承载力计算方法,对既有病害石拱桥的使用及加固改造带来明显困惑问题,结合有限元模拟分析,在现有研究成果基础上探索了计入风化及纵横向裂缝病害影响的石砌结构承载力估算方法,并将研究成果运用于重庆市涪陵区大溪河三号桥(60米跨径石拱桥)既有承载能力分析中。研究主要工作如下:探讨了计入缺陷、风化、横向裂缝、纵向裂缝对砌体结构承载能力影响的计算模式;分析了风化对石砌结构承载能力的影响,得出风化影响系数估算方法。依据有限元模型,研究了横向裂缝对石砌结构力学性能的影响,分析不同类型的横向裂缝(裂缝深度、裂缝条数)对石砌结构承载力造成的影响,得到计入横向裂缝影响的承载力折减系数估算方法。依据已有石砌结构长细比与稳定系数的理论关系,分析了不同类型纵向裂缝对石砌结构承载力的影响,得到计入纵向裂缝间距、长度、深度影响的承载力折减系数估算方法。介绍了课题组提出的一种石拱桥加固方案——用槽形钢筋混凝土肋对石砌主拱结构进行加固,阐述了加固应力及细部构造;依据上述成果对加固前的石砌主拱结构进行了计入风化和裂缝病害后的承载力评估,并对加固后桥梁进行了在不同荷载工况下的力学行为分析,结果表明该加固方法能够明显提升拱桥结构承载力和使用性能。
[Abstract]:In this paper, based on the national 973 project subproject undertaken by the tutor, the bearing capacity calculation method of stone masonry structure, which takes account of weathering and longitudinal and horizontal crack diseases, is lacking at present. In view of the obvious puzzling problem caused by the use and reinforcement of the existing stone arch bridge, combined with the finite element simulation analysis, the method of estimating the bearing capacity of stone masonry structure considering the influence of weathering and longitudinal and transverse cracks is explored on the basis of the existing research results. The research results are applied to the analysis of the existing bearing capacity of Daxihe No.3 Bridge (60 m span stone arch bridge) in Fuling District, Chongqing. The main work of this paper is as follows: the calculation model of bearing capacity of masonry structure by taking into account defects, weathering, transverse cracks and longitudinal cracks is discussed, and the influence of weathering on bearing capacity of stone masonry structure is analyzed, and the method of estimating weathering influence coefficient is obtained. Based on the finite element model, the effects of transverse cracks on the mechanical properties of stone masonry structures are studied, and the effects of different types of transverse cracks (crack depth, crack number) on the bearing capacity of stone masonry structures are analyzed. A method for estimating the reduction coefficient of bearing capacity considering the influence of transverse cracks is obtained. According to the theoretical relationship between the aspect ratio of stone masonry structure and the stability coefficient, the influence of different types of longitudinal cracks on the bearing capacity of stone masonry structure is analyzed, and the method of estimating the reduction coefficient of bearing capacity considering the influence of longitudinal crack spacing, length and depth is obtained. This paper introduces a kind of reinforcement scheme of stone arch bridge, which is reinforced concrete rib with groove shape to reinforce the main arch structure of stone masonry, and expounds the strengthening stress and detailed structure. According to the above results, the bearing capacity of the main arch structure before reinforcement is evaluated after weathering and crack diseases are taken into account, and the mechanical behavior of the strengthened bridge under different load conditions is analyzed. The results show that the reinforcement method can obviously improve the bearing capacity and service performance of arch bridge structure.
【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】：U441;U445.71

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