斜拉桥的缺损状况评估方案及剩余寿命预测方法研究

发布时间：2018-06-09 04:32

本文选题：斜拉桥 + 损伤　；参考：《重庆交通大学》2014年硕士论文

【摘要】：大型桥梁基于桥梁健康监测系统，对结构的损伤进行识别、评估，对剩余寿命进行预测，及时了解桥梁结构当前的实际运行状态就显得格外重要，关乎人民群众的生命财产安全。本文以目前国内外对桥梁损伤识别、评估方法的研究现状为基础，以装有健康监测系统的大跨度混凝土斜拉桥为背景，对主要病害的损伤识别、评估以及结构剩余寿命的预测进行了分析研究，具体如下： ①对目前斜拉桥存在的病害进行统计分析，归类出斜拉桥的主要病害以及产生的原因。 ②以涪陵乌江二桥为工程背景，建立有限元模型，并对该桥梁的动力特性进行分析，结果表明该桥的频率值较小，模态十分密集；对各阶的主导模态进行分类分析；提出根据损伤对应的力学症状数据库，反过来，通过对非确定性指标的综合运用，对损伤进行诊断，识别出损伤发生的位置和损伤程度的方法，并利用层次分析法中底层指标权重的确定方法，依据力学症状对损伤敏感性大小确定判断矩阵中的重要程度值，来确定各力学症状识别损伤的权重值。 ③用有限元降低刚度的方法分别模拟拉索和混凝土主梁单元的损伤，用降低刚度的比重模拟损伤的程度，对损伤后全桥各个力学指标进行分析，结果表明：失效索附近拉索索力变化、失效索和主梁锚固区主梁的应力变化、失效索所在桥塔的应力变化和顺桥向位移变化对拉索失效较为敏感，桥面系频率、主梁挠度变化则很小；模态曲率、主梁应力变化对主梁损伤较为敏感，，桥面系频率、主梁挠度变化则很小。 ④采用马尔科夫过程预测法对桥梁剩余寿命进行预测，该方法的核心是确定初始状态概率分布向量和转移概率矩阵。根据健康监测系统提供的大量数据，采用概率统计的方法确定初始状态概率分布向量，逆矩阵的方法求解转移概率矩阵。最后，对矮塔边跨侧装有拾振器的两根斜拉索用该方法进行了剩余寿命预测。
[Abstract]:A large bridge is based on the bridge health monitoring system. It is very important to predict the remaining life of the structural damage and predict the remaining life of the bridge. It is very important to know the actual operating state of the bridge structure in time, and it is related to the safety of the people's life and property.
Based on the current research status of bridge damage identification and evaluation methods at home and abroad, based on the large span concrete cable-stayed bridge equipped with health monitoring system, the damage identification, evaluation and residual life prediction of the main diseases are analyzed and studied.
First, statistical analysis of the existing diseases of the cable stayed bridge is made, and the main diseases and causes of the cable stayed bridge are classified.
Secondly, taking the second bridge in Wujiang, Fuling as the engineering background, the finite element model is established and the dynamic characteristics of the bridge are analyzed. The results show that the bridge has a small frequency and a very dense mode, and the dominant modes of each order are classified and analyzed. A database of the mechanical symptoms corresponding to the damage is proposed, and in turn, the non deterministic index is adopted. It is used to diagnose the damage, identify the location and damage degree of the damage, and use the method of determining the weight of the underlying index in the analytic hierarchy process, and determine the value of the important degree in the judgment matrix according to the damage sensitivity of the mechanical symptoms to determine the weight value of the damage of each mechanical symptom.
(3) to simulate the damage of cable and concrete main beam unit with the method of finite element stiffness reduction, and to simulate the damage degree by reducing the proportion of stiffness, the mechanical indexes of the whole bridge after damage are analyzed. The results show that the change of cable force near the failure cable, the stress change of the main beam in the anchorage zone of the failure cable and the main beam, and the bridge of the failure cable The variation of the stress and the lateral displacement of the tower is more sensitive to the failure of the cable. The frequency of the bridge deck and the deflection of the main beam are very small, and the change of the modal curvature and the main beam stress is more sensitive to the damage of the main beam, the frequency of the bridge deck system and the deflection of the main beam are small.
The Markov process prediction method is used to predict the remaining life of the bridge. The core of this method is to determine the probability distribution vector of the initial state and the transfer probability matrix. According to the large amount of data provided by the health monitoring system, the probability statistics method is used to determine the distribution vector of the initial state probability and the inverse matrix method is used to solve the transfer probability moment. Finally, the remaining life prediction of two inclined cables with vibration pickup on the side of the low tower is carried out by this method.
【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】：U448.27

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