在役斜拉桥时效风险分析

发布时间：2019-03-17 17:59

【摘要】：桥梁运营期间,除了承受各种设计荷载外,还长期面临环境侵蚀、超设计交通量和超载车辆、材料老化等与时间有关的不确定性因素影响,这将导致结构抗力逐渐退化,进一步可能导致安全风险。一旦出现事故,不仅有可能造成安全损失,同时还会带来重大的经济损失。如果能够准确的预测桥梁病害并提前采取养护措施,不仅可以避免灾难性的损失发生,而且避免大修大建的情况发生,这无疑将在安全和经济方面均达到最佳效果。因此,正确地预测桥梁运营期的风险状况具有重要的理论和应用价值。本文从风险分析、抗力退化等角度进行在役斜拉桥时效风险研究。主要内容概述如下：1)提出时效风险的概念以及在役斜拉桥时效风险分析理论框架,并给出了其基本分析流程；2)基于收缩、徐变、车辆荷载的分析,对在役斜拉桥的时效风险概率进行研究,并采用定性与定量相结合的方法进行时效风险损失的估算；3)提出了在役斜拉桥时效风险评价的评价原则和判定标准,以及建议了相应的时效风险应对措施；4)分别对钢结构构件、拉索构件和钢筋混凝土进行了抗力时效退化研究,探究它们的各自抗力退化规律,并推导出相应抗力退化理论公式；5)用本文所提的时效风险分析理论,对苏通大桥的正常使用阶段性能进行分析预测,得到该桥在运营期内的时效风险变化规律,并提出相应各关键风险阶段应该采取的控制措施。
[Abstract]:During the bridge operation, in addition to bearing all kinds of design loads, it also faces the influence of time-related uncertainties such as environmental erosion, over-designed traffic and overloading vehicles, material aging and so on, which will lead to the gradual degradation of structural resistance. It may further lead to security risks. In the event of an accident, it is possible not only to cause safety losses, but also to bring about significant economic losses. If the bridge disease can be predicted accurately and the maintenance measures can be taken in advance, not only the catastrophic loss can be avoided, but also the major repair and construction will be avoided. This will undoubtedly achieve the best effect in safety and economy. Therefore, it is of great theoretical and practical value to correctly predict the risk status of bridge operation period. This paper studies the time-effect risk of cable-stayed bridge in service from the angle of risk analysis, resistance degradation and so on. The main contents are summarized as follows: 1) the concept of limitation risk and the theoretical framework of limitation risk analysis of cable-stayed bridge in service are put forward, and its basic analysis process is given. 2) based on the analysis of shrinkage, creep and vehicle load, the time-risk probability of cable-stayed bridge in service is studied, and the quantitative and qualitative methods are used to estimate the time-dependent risk loss. 3) put forward the evaluation principle and criterion of the limitation risk evaluation of the cable-stayed bridge in service, and put forward the corresponding measures to deal with the time-effect risk; 4) the aging degradation of steel structural members, cable members and reinforced concrete is studied, and the corresponding theoretical formulas of resistance degradation are deduced. 5) based on the time-dependent risk analysis theory proposed in this paper, the performance of the Sutong Bridge during the normal period of operation is analyzed and predicted, and the variation rule of the time-effect risk of the bridge during the operation period is obtained. At the same time, the control measures should be taken in the corresponding key risk stages.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U448.27

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