混凝土连续刚构和斜拉桥损伤敏感性分析

发布时间：2018-04-19 23:36

本文选题：敏感性 + 桥梁病害　；参考：《长安大学》2015年硕士论文

【摘要】：进入新世纪以来,中国基础设施建设发展迅速,桥梁事业也发展到一个全新的阶段。斜拉桥由于其经济性好,结构受力合理且跨越能力大,成为大跨桥梁中的主流桥型;预应力混凝土连续刚构桥也以其造型优美、跨越能力大和经济性好等优点,成为中等跨径的桥梁中的有力竞争者。但是经济刺激下的快速发展,使得现有桥梁存在着许多损伤与病害,且日益严重,从而导致桥梁结构耐久性、承载能力降低,桥梁的运营状况满足不了其正常使用阶段的需求。如何及早地发现结构的损伤已成为桥梁界面临的重要课题,结构的健康监测损伤识别也成为了当下的研究热点。本文选取一座混凝土连续刚构桥和一座混凝土斜拉桥,在混凝土桥梁病害调查的基础上,探讨结构易于发生损伤的部位以及模拟损伤发生之后对结构静力与动力特性的影响。通过分析损伤识别过程中各个指标对于损伤位置和程度的敏感性,给出不同指标的识别能力,为结构的损伤识别提供一些参考。通过文献收集对混凝土桥梁进行病害总结,发现对于混凝土连续刚构桥,主梁开裂和跨中累计下挠过大是常见病害,尤其以主跨跨中、四分点以为支点截面附近位置更加突出;对于混凝土斜拉桥,斜拉索病害普遍突出,其次为塔根截面和拉索锚固区域。混凝土连续刚构桥和斜拉桥主梁敏感性分析实例部分,结合病害调查通过折减单元刚度模拟正常使用阶段主梁主跨跨中、四分点等不同位置出现不同程度的损伤,分析结构损伤识别中的各种动力指标对损伤的敏感程度。结果表明,各个指标的敏感程度不同,基于模态曲率和柔度矩阵的指标对于损伤位置更加敏感。混凝土斜拉桥拉索敏感性分析部分,通过折减拉索面积和张拉力模拟拉索出现不同程度损伤,分析损伤对于主梁挠度、拉索索力和结构模态频率的影响。结果表明,个别拉索损伤对结构模态频率影响很小;拉索损伤后,对应主梁位置会出现下挠,并且长索对挠度的影响更大;拉索损伤会引起邻近拉索索力增大,且这种影响是局部的。本文通过敏感性实例分析,考察不同指标对于损伤的敏感程度,对于主梁出现损伤,基于模态曲率和柔度矩阵的指标更加敏感;对于个别拉索出现损伤,结构的静力指标更加敏感,对结构动力特性影响不明显。
[Abstract]:Since the new century, China's infrastructure construction has developed rapidly and Bridge undertakings have developed to a new stage. The cable-stayed bridge has become the mainstream bridge type in large span bridges because of its good economy, reasonable structure and great spanning ability. The prestressed concrete continuous rigid frame bridge also has beautiful shape, great spanning ability and good economy. It has become a strong competitor in the medium span bridge. However, the rapid development of economic stimulation makes the existing bridge many damage and disease, and it is increasingly serious, which leads to the durability of the bridge structure, the reduction of bearing capacity, and the operation condition of the bridge is not satisfied with the demand of its normal use stage. The damage of structure has become an important subject in the bridge circle, and the identification of structural health monitoring damage has become a hot spot of research. A concrete continuous rigid frame bridge and a concrete cable-stayed bridge are selected in this paper. On the basis of the investigation of the disease of concrete bridges, the location of the structure easily damaged and the occurrence of the simulated damage are discussed. After analyzing the influence of the static and dynamic characteristics of the structure, by analyzing the sensitivity of each index to the location and degree of damage in the process of damage identification, the recognition ability of different indexes is given to provide some reference for the damage identification of the structure. The cracking of the main beam and the cumulative oversize in the span are common diseases, especially in the middle span of the main span, and the four point is more prominent near the pivot section. For the concrete cable-stayed bridge, the diseases of the cable are generally prominent, followed by the section of the tower root and the cable anchorage area. The results show that the sensitivity of various dynamic indexes in structural damage identification is different, and the sensitivity of each index is different, based on the index of modal curvature and flexibility matrix. It is more sensitive to the damage position. The damage to the cable tension, cable force and structural modal frequency of the main beam is analyzed by the damage of the cable area and the Zhang Lali simulated cable. The results show that the damage to the structural modal frequency is very small; the cable damage is damaged. After that, the deflection of the main beam will appear, and the long cable has more influence on the deflection, and the cable damage will cause the increase of the cable force of the adjacent cable, and this effect is partial. In this paper, the sensitivity of different indexes to the damage, the damage to the main beam and the index based on the modal curvature and the flexibility matrix are analyzed in this paper. For the damage of individual cables, the static index of the structure is more sensitive, and the influence on the dynamic characteristics of the structure is not obvious.

【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U446

【参考文献】