基于长期监测数据的混凝土梁桥健康状态评判方法研究

发布时间：2018-09-14 20:21

【摘要】：桥梁是公路的咽喉，其承载能力是保证公路全线安全性的关键。近年来，随着国民经济的快速发展，桥梁长时间担当着繁重的交通任务，因此桥梁结构的安全状态越来越受人们的重视。常规的检查难以持续和及时地把握桥梁的安全状态，而有效的在线健康监测和安全评估可以提高结构的日常安全运营水平，以避免重大事故的发生。本文在结合国内外桥梁健康监测及安全状态评估理论和技术的基础上，以基于长期监测数据的混凝土梁桥健康状态判断方法为研究重点，以江津长江大桥健康监测系统为工程背景，立足于工程实际，对桥梁健康监测与安全状态评判中的一系列技术问题进行了深入、系统的研究，论文的主要研究内容和研究结果包括： ①首先介绍了桥梁结构健康监测的意义和目的以及目前桥梁结构健康监测与安全评价方法的研究现状。通过查找大量文献资料，归纳总结了目前国内已经安装健康监测系统的代表性桥梁及其系统布置情况，同时对现阶段尚存在的一些问题进行了分析。 ②介绍了时间序列分析的理论和方法，为海量桥梁监测数据的处理提供了新的思路。利用MATLAB数学工具，首先对桥梁监测数据进行预处理，然后通过时间序列的数据挖掘功能，对监测数据进行时间序列建模分析，从而实现对监测数据的预测效果，使得桥梁健康状态的预警成为可能。 ③研究桥梁实时监测数据中的温度效应，采用数理统计线性回归分析方法，找到温度与结构指标监测数据之间的关系，剔除温度荷载的影响后，获得能反应桥梁状态的特征数据。 ④采用基于层次分析法及变权综合原理来建立混凝土梁桥健康状态评估体系及指标评价体系。首先介绍了层次分析法的基本原理、基本步骤及权重的计算方法；其次通过无量纲化处理和底层指标评价的分级评定为不同监测指标间的数据评价提供可能，利用结构有限元模型的计算分析，列出了挠度和应力等底层指标在荷载组合下的阈值，找到了一种脱离人为主观因素、相对稳定的构造应力和挠度测点权重判断矩阵的方法；最后采用变权综合原理对全桥结构的安全性能进行了评估，解决了由于某一些因素权重较小，在总结果中不明显，，但可能会影响整个桥梁工作状态的问题，应用这种方法使得评估结果更加合理。
[Abstract]:Bridge is the throat of highway, and its bearing capacity is the key to ensure the safety of the whole highway. In recent years, with the rapid development of the national economy, bridges take on heavy traffic tasks for a long time, so more and more attention is paid to the safety state of bridge structures. Conventional inspection is difficult to grasp the safety status of bridges in a sustained and timely manner. Effective online health monitoring and safety assessment can improve the daily safety operation level of the structure to avoid serious accidents. Based on the theory and technology of bridge health monitoring and safety state assessment at home and abroad, this paper focuses on the method of judging the health state of concrete beam bridge based on long-term monitoring data. Taking the health monitoring system of Jiang Jin Yangtze River Bridge as the engineering background and based on the engineering practice, a series of technical problems in bridge health monitoring and safety state evaluation are studied in depth and systematically. The main contents and results of this paper are as follows: 1 the significance and purpose of health monitoring of bridge structures and the present research status of health monitoring and safety assessment methods of bridge structures are introduced. By looking up a large number of documents and materials, this paper summarizes the representative bridges and their system layout that have been installed in our country at present. At the same time, some existing problems at present are analyzed. 2 the theory and method of time series analysis are introduced, which provides a new idea for the processing of massive bridge monitoring data. Using the MATLAB mathematical tool, the bridge monitoring data is preprocessed first, and then through the data mining function of the time series, the monitoring data is modeled and analyzed in time series, so that the prediction effect of the monitoring data can be realized. It is possible to make the early warning of bridge health status possible. 3 studying the temperature effect in bridge real-time monitoring data, using mathematical statistical linear regression analysis method, to find the relationship between temperature and structural index monitoring data. After excluding the influence of temperature load, the characteristic data of bridge state can be obtained. 4 based on AHP and variable weight synthesis principle, the evaluation system and index evaluation system of concrete beam bridge health state are established. Firstly, the paper introduces the basic principle, basic steps and calculation method of weight of AHP. Secondly, it provides the possibility for data evaluation among different monitoring indexes by dimensionless processing and grading evaluation of bottom index evaluation. Based on the calculation and analysis of the finite element model of the structure, the threshold values of the bottom indexes such as deflection and stress under the load combination are listed, and a method of determining the weight matrix of the structural stress and deflection measuring points, which is independent of the artificial subjective factors and relatively stable, is found. Finally, the variable weight synthesis principle is used to evaluate the safety performance of the whole bridge structure, which solves the problem that some factors have less weight and are not obvious in the total result, but may affect the working state of the whole bridge. The application of this method makes the evaluation results more reasonable.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U446

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