锈胀损伤钢筋混凝土拱肋的静力特性研究

发布时间：2018-07-29 17:49

【摘要】：自从第一座拱桥诞生于罗马时代的英国以来,随着新材料新技术的快速发展,在现今交通网络中,拱桥已占相当大的比例,尤其钢筋混凝土拱桥。这些桥梁经过多年的工作,加上不良环境的侵蚀、自然因素的影响、材料性质变化等原因,许多在役桥梁产生了不同程度的损坏。统计表明,钢筋锈蚀已成为钢筋混凝土(RC)拱桥损伤的主要原因之一。同时,由锈蚀引起的开裂损伤也已成为锈蚀构件剩余承载能力评估的关键。由于既有拱桥在混凝土开裂、钢筋锈蚀等方面有着很大的不确定性,因此,对RC拱肋静力特性的准确评定仍具有很大的挑战性。本文对国内外锈胀损伤RC拱桥的研究情况进行了总结。锈蚀RC结构的静力特性研究目前多围绕RC梁开展,由于拱结构的特殊性,对锈胀损伤作用下RC拱肋的静力特性研究非常少。基于此种情况,本文运用加速锈蚀法制作了3片锈胀损伤程度不同的圆弧拱肋构件及1片未锈蚀构件作对比试验。通过加载破坏试验,研究了不同锈胀损伤下RC拱肋的受力特性、裂缝形成及扩展、破坏形态及影响承载力退化的主要因素,对加载后的锈胀损伤RC构件的裂缝发展情况做了进一步探讨,并分析了不同锈胀损伤下RC拱肋关键截面处的荷载—挠度、荷载—应变关系,并对构件的失效模式及承载力的变化规律进行了对比。最后,本文以偏心受压构件的受力状态为依据,立足于现有计算理论,提出了锈胀损伤RC拱肋构件承载能力的计算方法并建立了计算模型,对比本试验中的数据结果并做相应分析研究。在对构件进行静力特性研究时,通常采用试验研究和理论分析相结合的方法。本文对锈胀损伤RC拱肋所做工作丰富了锈蚀构件耐久性理论研究,为在役RC拱桥的维修加固提供了科学依据。
[Abstract]:Since the first arch bridge was born in England in Rome, with the rapid development of new materials and new technology, arch bridge has occupied a large proportion in the transportation network nowadays, especially reinforced concrete arch bridge. After many years of work, many bridges in service have been damaged to varying degrees due to the erosion of the bad environment, the influence of natural factors, the change of material properties, and so on. Statistics show that the corrosion of steel bar has become one of the main causes of damage of reinforced concrete (RC) arch bridge. At the same time, cracking damage caused by corrosion has become the key to evaluate the residual bearing capacity of corroded members. Due to the uncertainty of concrete cracking and steel corrosion of existing arch bridges, it is still a challenge to accurately evaluate the static characteristics of RC arch ribs. This paper summarizes the research situation of RC arch bridge damaged by rust expansion at home and abroad. The research on the static characteristics of corroded RC structures is mostly carried out around RC beams at present. Due to the particularity of arch structures, there is little research on the static characteristics of RC arch ribs under the action of rust expansion damage. Based on this situation, three arc-arch rib members with different damage degree of rust expansion and one non-corroded member are made by accelerated corrosion method. In this paper, the stress characteristics, crack formation and propagation, failure form and main factors affecting bearing capacity degradation of RC arch rib under different rust expansion damage are studied by loading failure test. The crack development of RC members with corrosion damage after loading is further discussed, and the load-deflection, load-strain relationship at key sections of RC arch rib under different corrosion damage is analyzed. The failure mode and bearing capacity of members are compared. Finally, on the basis of the stress state of eccentric compression members and based on the existing calculation theory, this paper puts forward the calculation method of the bearing capacity of RC arch ribbed members damaged by rust expansion and establishes the calculation model. Compare the data of this experiment and do the corresponding analysis. In the study of static characteristics of components, the method of combining experimental research with theoretical analysis is usually adopted. The work done in this paper enriches the theoretical study on the durability of corroded RC arch rib and provides a scientific basis for the maintenance and reinforcement of RC arch bridge in service.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U448.22

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