环境侵蚀作用下桥梁结构加固模型疲劳试验研究

发布时间：2018-08-08 21:53

【摘要】：交通设施是国家经济和社会发展的基础工程,其中桥梁是保障交通正常运行的关键性结构。在长期的运行中,桥梁结构经受不同的外荷载和环境的共同作用,导致结构出现不同类型和程度的损伤,往往需要进行加固维修来维持其正常使用状态或延长其使用寿命。但是加固后的桥梁结构仍然遭受车辆荷载和环境侵蚀,加固后结构的耐久性劣化及疲劳寿命需得到广泛关注。因此开展环境侵蚀作用下桥梁结构加固模型疲劳试验研究,对于完善桥梁加固的耐久性,确保桥梁的运行安全,延长加固桥梁的使用寿命具有重要的实际意义。本文针对疲劳损伤大尺寸预应力空心板梁(构件),采用粘碳纤维布和粘钢板两种加固方法,针对碳化和冻融循环的侵蚀作用,开展桥梁加固结构耐久性劣化试验及其疲劳特性试验,主要工作如下:(1)对粘碳纤维布和钢板两种加固方法的构件开展动静载试验,分析了粘碳纤维布与粘钢板两种加固方法的加固效果。(2)针对不同加固方法和不同环境侵蚀劣化的试验板,开展了疲劳试验。(3)总结了加固构件在受到环境侵蚀后的挠度、应变、动态位移、基频和阻尼随疲劳过程的变化规律,揭示了加固构件在环境侵蚀作用下疲劳耐久性衰退机理。(4)对比分析了不同环境侵蚀作用下同一加固方法以及同一环境作用下不同加固方法加固构件的疲劳特性,总结了加固方法和侵蚀因素对桥梁结构疲劳特性的影响。(5)分析了环境侵蚀作用下加固构件疲劳次数与挠度变化之间的关系,得到了疲劳次数与挠度增加系数二者之间的相关关系。环境侵蚀作用下桥梁结构加固模型疲劳试验研究能够对损伤加固桥梁加固方案的确定、认识加固构件耐久性劣化机理、加固桥梁的检测评价与寿命预测提供一定的理论支撑。
[Abstract]:Transportation facilities are the basic engineering of national economic and social development, among which bridge is the key structure to ensure the normal operation of traffic. In the long-term operation, the bridge structure is subjected to different external loads and environment, resulting in different types and degrees of damage to the structure, it is often necessary to carry out reinforcement and maintenance to maintain its normal service state or prolong its service life. However, the strengthened bridge structure is still subject to vehicle load and environmental erosion, and the durability deterioration and fatigue life of the strengthened bridge structure need to be paid more attention. Therefore, it is of great practical significance to study the fatigue test of bridge structure strengthening model under the action of environmental erosion to improve the durability of bridge reinforcement, ensure the safety of bridge operation and prolong the service life of strengthened bridge. In this paper, aiming at fatigue damage large size prestressed hollow slab beams (members), two reinforcement methods, viscous carbon fiber sheet (CFRP) and bonded steel plate, are adopted to deal with the erosion effect of carbonization and freeze-thaw cycle. The main work of this paper is as follows: (1) the static and dynamic load tests are carried out on the members of the two reinforcement methods, the viscous carbon fiber sheet and the steel plate. In this paper, the effect of two reinforcement methods, carbon fiber sheet and steel plate, is analyzed. (2) fatigue tests are carried out for the test plates with different strengthening methods and different environmental erosion degradation. (3) the deflection and strain of the strengthened members after environmental erosion are summarized. The variation of dynamic displacement, fundamental frequency and damping with fatigue process, The fatigue durability degradation mechanism of strengthened members under environmental erosion is revealed. (4) the fatigue characteristics of members strengthened with the same reinforcement method under different environmental erosion and with different strengthening methods under the same environment are analyzed. The effects of strengthening methods and erosion factors on fatigue characteristics of bridge structures are summarized. (5) the relationship between fatigue times and deflection changes of strengthened members under environmental erosion is analyzed. The correlation between fatigue times and deflection increase coefficient is obtained. The fatigue test study of bridge structure strengthening model under the action of environmental erosion can provide certain theoretical support for the determination of the bridge strengthening scheme, the understanding of the durability deterioration mechanism of the strengthened members, the detection, evaluation and life prediction of the strengthened bridge.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U446.1

【相似文献】