基于静态监测数据的桥梁结构状态评估和预警方法研究

发布时间：2018-02-10 05:05

  本文关键词： 结构健康监测 状态评估 温度 纵向位移 静应变　出处：《东南大学》2015年硕士论文　论文类型：学位论文

【摘要】：国内外不少学者已展开了基于整体动力特性的桥梁结构状态评估,但是由于桥梁结构复杂、体量巨大、局部损伤的不敏感性以及环境因素的影响,基于动力参数的监测难以有效应用于结构状态评估。基于静态监测数据的桥梁结构状态评估和预警方法研究对其安全运营具有重要意义,是目前大跨桥梁健康监测领域的热点。结构健康监测系统在大跨桥梁上的成功实施为保证桥梁结构的安全性、适用性、耐久性提供良好的平台。随着实时监测数据的不断积累,有效分析和处理海量健康监测数据,建立环境作用、交通荷载等与桥梁结构输出状态间关系的响应机理、提升桥梁结构设计水平和分析技术是健康监测领域的重要问题。本文以高速铁路桥梁大胜关长江大桥为研究对象,基于健康监测系统获取的监测数据,系统研究了桥梁温度、纵向位移、静应变与环境荷载作用相关模型,准确建立了环境荷载作用下的结构状态评估及预警方法研究,主要内容包括：(1)系统地研究了大胜关长江大桥连续钢拱桁梁2013年的温度监测数据,采用极值分析和统计分析方法详细考察了钢拱桁梁的温度分布特征和温差分布特征,后利用统计学方法对边桁拱整体竖向温差和杆构件横截面温差的正温差和负温差样本分别进行概率统计特征分析,确定其Weibull概率密度函数的参数估计值,在此基础上计算得出温差标准值。(2)系统地研究了大胜关长江大桥支座纵向位移的变化特点及其相关性规律,支座纵向位移与温度呈现出良好的线性关系,支座纵向位移与温差呈现出一定的线性关系,采用多元线性回归方程建立支座纵向位移与温度场之间的线性相关特性,并利用拉格朗日插值建立不同支座纵向位移之间的线性相关特性,建立的数学模型可有效反映钢桁拱梁在初始状态的纵向伸缩性能,而且可以有效地模拟主梁纵向位移的变化规律；利用均值控制图法来对梁端位移进行异常监控,测试结果验证了该方法的有效性。(3)系统地研究了南京大胜关长江大桥钢桁桥静应变的变化规律,大胜关长江大桥主梁静应变主要由三部分组成：由温度引起的静应变SⅠ、由温差引起的静应变SⅡ,以及由列车荷载引起的静应变SⅢ,且由列车荷载引起的静应变显著低于由温度和温差带来的影响；引入小波包分解技术剔除由车辆荷载引起的静应变效应并提取出由温度场引起的静应变效应,然后采用数学建模方法建立静应变与温度场之间的多元线性回归模型,并进一步利用主成分分析方法简化多元线性回归模型的分析变量。最后提出三种大胜关长江大桥的静力承载性能退化规律来对大胜关长江大桥的静力承载性能进行评估。
[Abstract]:Many scholars at home and abroad have carried out the state assessment of bridge structure based on the global dynamic characteristics. However, due to the complexity of the bridge structure, huge volume, insensitivity of local damage and the influence of environmental factors, many scholars at home and abroad have carried out the assessment of bridge structure. Monitoring based on dynamic parameters is difficult to be effectively applied to structural state assessment. The study of bridge structure state assessment and early warning method based on static monitoring data is of great significance to its safe operation. The successful implementation of structural health monitoring system on long-span bridges provides a good platform for ensuring the safety, applicability and durability of bridge structures. With the continuous accumulation of real-time monitoring data, the structural health monitoring system is a hot spot in the field of health monitoring of long-span bridges. To analyze and deal with the massive health monitoring data effectively, to establish the response mechanism of the relationship between the environmental function, traffic load and the output state of the bridge structure. It is an important problem in the field of health monitoring to improve the design level and analysis technology of bridge structure. This paper takes the Dashengguan Yangtze River Bridge of high-speed railway bridge as the research object, based on the monitoring data obtained by the health monitoring system, systematically studies the bridge temperature. The model of longitudinal displacement, static strain and environmental load is established, and the structural state evaluation and early warning method under the action of environmental load are established accurately. The temperature monitoring data of continuous steel arch truss beam of Dashengguan Yangtze River Bridge on 2013 are studied systematically. The temperature distribution and temperature difference distribution characteristics of steel arch truss beam are investigated in detail by extreme value analysis and statistical analysis. Then the positive and negative temperature difference samples of the whole vertical temperature difference of side truss arch and the cross section temperature difference of bar member are analyzed by statistical method, and the parameter estimation value of Weibull probability density function is determined. On this basis, the standard value of temperature difference is obtained.) the variation characteristics of the longitudinal displacement of the support of the Dashengguan Yangtze River Bridge and its correlation law are systematically studied. The longitudinal displacement of the support has a good linear relationship with the temperature. There is a linear relationship between the longitudinal displacement of the bearing and the temperature difference. The linear correlation between the longitudinal displacement of the bearing and the temperature field is established by using the multivariate linear regression equation. The linear correlation between the longitudinal displacement of different supports is established by Lagrange interpolation. The established mathematical model can effectively reflect the longitudinal scalability of steel truss arch beam in the initial state. Moreover, it can effectively simulate the variation law of longitudinal displacement of the main beam, and use the mean value control chart method to monitor the displacement of the end of the beam. The test results verify the validity of this method. (3) the static strain of the steel truss bridge of the Dashengguan Yangtze River Bridge in Nanjing is studied systematically. The static strain of the main girder of the Dashengguan Yangtze River Bridge is mainly composed of three parts: the static strain S 鈪，

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