斜拉桥拉索损伤对桥梁结构性能的影响研究

发布时间：2018-10-31 07:37

【摘要】：斜拉索作为斜拉桥的主要承重和传力构件,其质量上要求具有良好的刚度、强度、抗疲劳强度以及耐久性。然而,斜拉索由于长期承受疲劳荷载,加之暴露在自然环境中,钢丝索体和锚具结构件遭受腐蚀破坏的可能性较大。斜拉索的损害会对斜拉桥的整体性能和正常运行造成很大影响。对于斜拉桥来说,钢材的应力松弛、疲劳、腐蚀以及桥梁变形等不利因素的影响会使斜拉桥容易发生局部的破损。从表面上看这些局部破损虽并不会导致整个结构短时间内发生破坏,但从长期运营来看,拉索损伤已经对桥梁结构的安全构成了潜在的危险。拉索局部破坏会导致斜拉桥整体刚度的下降以及承载能力的显著降低,影响车辆的正常行驶,严重时斜拉桥甚至会出现失稳破坏,这不仅会导致结构自身使用寿命缩短,而且会对行人的生命和财产安全产生威胁。若能够及时发现斜拉桥破损之处,并及时判断出破损的程度以及破损的位置,维修人员就能准确制定出可行的维修方案,并且及时对损伤部位进行维修。本文主要研究内容有以下几方面:首先,简述了斜拉桥的现状和发展趋势,并介绍了拉索性能特性,通过分析现有斜拉索使用过程的损伤状况,提出斜拉桥拉索损伤危害性分析问题。其次,通过分析拉索不同情况损伤下桥梁结构响应,发现斜拉桥主梁线形、拉索内力、索塔位移以及桥梁动力性能在拉索不同损伤情况下的变化规律。最后,根据拉索损伤及断索危害性研究,结合拉索损伤检测技术,研究较为可行的检测方法。提出通过对主梁、拉索以及主塔的健康监测进行斜拉桥健康状态预警的可能性。
[Abstract]:As the main load-bearing and force-transfer member of cable-stayed bridge, the cable is required to have good stiffness, strength, fatigue strength and durability. However due to long term fatigue load and exposure to natural environment the cable body and anchor structure are more likely to be corroded and destroyed. The damage of cable will greatly affect the overall performance and normal operation of the cable-stayed bridge. For cable-stayed bridge, the influence of steel stress relaxation, fatigue, corrosion and bridge deformation will make the cable-stayed bridge prone to local damage. On the surface these local damage will not lead to the damage of the whole structure in a short time but from the long-term operation the cable damage has posed a potential danger to the safety of the bridge structure. The local failure of cable will lead to the decrease of the overall stiffness of cable-stayed bridge and the significant decrease of bearing capacity, which will affect the normal running of vehicles, and even lead to unstable damage of cable-stayed bridge when serious, which will not only shorten the service life of the structure itself, but also reduce the service life of the cable-stayed bridge. It also threatens the lives and property of pedestrians. If the damaged place of the cable-stayed bridge can be found in time and the degree and position of the damage can be judged in time, the maintenance personnel can accurately work out the feasible maintenance plan and carry out the repair of the damaged part in time. The main contents of this paper are as follows: firstly, the present situation and development trend of cable-stayed bridge are briefly described, and the performance characteristics of cable are introduced. The problem of cable damage analysis of cable-stayed bridge is put forward. Secondly, by analyzing the structural response of the cable-stayed bridge under different damage conditions, it is found that the main girder alignment, cable internal force, tower displacement and dynamic performance of the cable-stayed bridge change under different damage conditions. Finally, according to the research of cable damage and cable breakage, combined with cable damage detection technology, the more feasible detection method is studied. The possibility of early warning of the health status of cable-stayed bridge by monitoring the health of main girder, cable and tower is put forward.
【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;U448.27

【参考文献】