大跨度斜拉桥运营期性能监测与评估

发布时间：2018-10-20 19:49

【摘要】：为研究大跨度斜拉桥运营期的性能监测与评估方法,建立稳定高效的健康监测系统,在总结以往斜拉桥健康监测所存在的问题基础上,对以下几个方面的工作进行了研究：1、针对斜拉桥上传感器布设总类多、数量大的特点,对其网络系统的拓扑结构进行了优化研究,通过总线技术的应用,将传感系统设定成一种现场总线网络结构结合星型网络结构的综合体系,并对斜拉桥整体基于总线型光纤传感网络的布置方案进行了研究,特别对采用总线技术的结构优化方案以及系统监测信息的无线传输方案进行了研究。2、分析了斜拉桥非线性振动的特征,对拉索的非线性振动进行了参数分析,并对其非线性内共振,参数振动及涡振进行了理论分析和计算。基于分析结果,提出了对拉索系统整体涡振安定性(cable system vortex-induced vibration stability, CSVVS)的评价方法,并基于风环境监测信息及索频信息对拉索的运营状态进行整体评估同时对潜在运营风险进行预测。3、采用雨流计数分析手段,在既有数据分析软件的基础上,对结构及构件的疲劳载荷谱进行统计分析,并基于统计结果对疲劳进行评估；同时给出了基于少量测试数据的拟合分析方法。分析指出当测试数据完备时应首先使用统计分析法,以避免拟合分析法遗漏孤立幅值带来分析误差。在Maple平台上编写了经过改进的雨流计数分析程序,并通过一组模拟数据的人工作图分析验证了该算法的有效性。4、分析认为拉索系统的锈蚀是影响结构耐久性及安全性的重要因素,由于目前对拉索系统的锈蚀监测还处于初级阶段,文中基于对各种监测方法的分析总结,提出了锚具视频监测结合索体端部声发射监测,并索体中段自爬升磁漏监测的综合监测方案。5、鉴于CWT计算效率的问题,对CWT进行了离散化研究。由于目前DWT多采用重复计算多次离散点积的特点,文中提出了带平移参数b的算法,并在通用数学分析软件Maple的基础上编写了带参数的DWT算法。以所建立的斜拉桥模型在选定的时程荷载条件下对DWT应用于时域测试的损伤分析进行了验证,结果表明DWT继承了CWT的所有优点,且该方法可以有效识别出时程数据中所包含的结构损伤相关信息,同时在计算效率上与传统方法相比得到了显著改善。6、鉴于斜拉桥失效形式多样,本文对其中几种典型的失效模式进行了研究,指出基于拉索应力失效、主梁挠度及应力失效是斜拉桥最基本的失效模式。并利用蒙特卡洛随机抽样结合多参数响应面分析的综合算法,对结构整体可靠性能进行分析。
[Abstract]:In order to study the performance monitoring and evaluation method of long-span cable-stayed bridges during operation, and to establish a stable and efficient health monitoring system, based on summarizing the problems existing in the health monitoring of cable-stayed bridges in the past, The following aspects are studied: 1. Aiming at the characteristics of the large number of sensors in cable-stayed bridge, the topology of the network system is optimized and applied by bus technology. The sensor system is set up as a comprehensive system of fieldbus network structure combined with star network structure, and the layout scheme of cable-stayed bridge based on bus-type fiber-optic sensor network is studied. Especially, the structure optimization scheme based on bus technology and the wireless transmission scheme of system monitoring information are studied. 2. The characteristics of nonlinear vibration of cable-stayed bridge are analyzed, and the nonlinear vibration of cable is analyzed. The nonlinear internal resonance, parametric vibration and vortex vibration are theoretically analyzed and calculated. Based on the analysis results, a method for evaluating the overall vortex-vibration stability of cable system (cable system vortex-induced vibration stability, CSVVS) is proposed. On the basis of wind environment monitoring information and cable frequency information, the operation state of cable is evaluated as a whole and the potential operational risk is forecasted. 3. Based on the existing data analysis software, rain flow counting analysis method is adopted. The fatigue load spectrum of structures and components is statistically analyzed, and the fatigue is evaluated based on the statistical results, and a fitting analysis method based on a small amount of test data is given. It is pointed out that when the test data are complete, the statistical analysis method should be used first, so as to avoid the analysis error caused by missing the isolated amplitude value of the fitting analysis method. An improved rain flow analysis program is developed on the Maple platform. The validity of the algorithm is verified by the human working graph analysis of a set of simulated data. 4. The corrosion of the cable system is considered to be an important factor affecting the durability and safety of the structure. Because the corrosion monitoring of cable system is still in the primary stage, based on the analysis and summary of various monitoring methods, the paper puts forward the anchor video monitoring combined with cable end acoustic emission monitoring. In view of the efficiency of CWT calculation, the discretization of CWT is studied in view of the comprehensive monitoring scheme of self-climbing flux leakage monitoring in the middle part of cable body. Due to the characteristic of repeated calculation of multiple discrete dot products in DWT at present, an algorithm with translation parameter b is proposed, and a DWT algorithm with parameters is compiled on the basis of the general mathematical analysis software Maple. The damage analysis of DWT applied to time-domain test is verified by the established cable-stayed bridge model under selected time-history load conditions. The results show that DWT inherits all the advantages of CWT. This method can effectively identify the structural damage related information contained in the time-history data, at the same time, the computational efficiency is significantly improved compared with the traditional method. 6, in view of the variety of failure forms of cable-stayed bridge, In this paper, several typical failure modes are studied. It is pointed out that the deflection and stress failure of the main beam are the most basic failure modes of cable-stayed bridges based on cable stress failure. The reliability of the structure is analyzed by Monte Carlo random sampling and multi-parameter response surface analysis.
【学位授予单位】：西南交通大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：U446;U448.27

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