苏通大桥风致风险分析

发布时间：2018-07-31 10:53

【摘要】：所有自然灾害中,风灾是发生最为频繁也是影响最为广泛的一种,桥梁结构尤其是缆索承重桥梁更是时时刻刻面临风灾的威胁。斜拉桥作为缆索承重桥梁的一种,其发展趋势体现在跨径的不断增大和材料的轻质高强,使得现代斜拉桥对风荷载越来越敏感。斜拉桥在运营期间时刻处于风荷载作用下,随时会面临风致灾害的考验。风灾一般分为颤振、驰振、静风失稳、抖振、拉索风雨振等。为了能够随时掌握结构的抗风性能并且保证其处于安全的状态,需要对处于运营期的桥梁进行风致风险评估。本文以苏通大桥为工程背景,基于各类风致响应,对其运营期的风致风险进行评估。主要内容概述如下：(1)分别对苏通大桥静风响应、静风失稳、颤振和抖振响应展开分析,并重点探讨不同的参数对于风致响应的影响。旨在为苏通大桥运营期风致风险评估计算中的不确定性分析做准备。(2)提出风致时效风险的概念和理论体系,将运营期风致风险分为失稳破坏、位移超限和应力超限,并引入材料性能退化这一时效因素,发现性能退化会对最终风险评估结果产生影响。(3)在风致时效风险理论的基础上,按照时效风险体系对苏通大桥进行运营期风致风险评估。结果表明,失稳破坏、位移超限和应力超限风险均随着材料性能的退化而不同程度的上升。
[Abstract]:Among all natural disasters, wind disaster is the most frequent and the most widespread impact, bridge structure, especially cable bearing bridge is always facing the threat of wind disaster. As a kind of cable-bearing bridge, cable-stayed bridge is more and more sensitive to wind load due to the increasing span and the high strength of materials. The cable-stayed bridge will face the test of wind-induced disaster at any time when it is under the action of wind load during operation. Wind disasters are generally divided into flutter, galloping, static wind instability, buffeting, cable wind vibration and so on. In order to grasp the wind-resistant performance of the structure at any time and to ensure that it is in a safe state, the wind-induced risk assessment of the bridge in operation period is needed. Based on all kinds of wind-induced responses, the wind-induced risk of Sutong Bridge is evaluated in this paper. The main contents are summarized as follows: (1) the static wind response, static wind instability, flutter and buffeting response of Sutong Bridge are analyzed, and the effects of different parameters on wind-induced response are discussed. The purpose of this paper is to prepare for the uncertainty analysis of wind-induced risk assessment and calculation of Sutong Bridge during operation period. (2) the concept and theoretical system of wind-induced aging risk are put forward. The wind-induced risk during operation period is divided into unstable failure, displacement overlimit and stress overlimit. By introducing the aging factor of material property degradation, it is found that the degradation of performance will have an impact on the final risk assessment results. (3) based on the wind-induced aging risk theory, the wind-induced risk assessment of Sutong Bridge is carried out according to the aging risk system. The results show that the risks of instability, displacement and stress are increased with the degradation of material properties.
【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】：U447

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