运营期独塔自锚式悬索桥监测与状态评估研究

发布时间：2018-03-21 16:55

本文选题：独塔自锚式悬索桥　切入点：结构安全影响因素　出处：《东南大学》2015年硕士论文　论文类型：学位论文

【摘要】：独塔自锚式悬索桥作为一种新型的桥梁形式,近十几年在国内外得到了迅速的发展,由于其结构形式复杂,且对该类桥型的监测和研究较少,因此本文以南京江心洲大桥为工程背景,对独塔自锚式悬索桥运营期间的监测及状态评估进行了较为系统的研究,主要研究工作和成果体现在以下几个方面：1、自锚式悬索桥结构安全影响因素及监测内容分析针对自锚式悬索桥自身结构特点,分析了其主要结构部分,包括缆吊体系、主塔结构、加劲梁结构的安全影响因素；在结构安全影响因素分析基础上,确定自锚式悬索桥安全监测内容及定期检测内容。2、运营期各监测内容对应监测方法研究针对南京江心洲大桥,对静、动力传感器测点布设方法进行了研究。在移动荷载分析的基础上,考虑荷载最不利组合,确定主缆内力、主梁应力、主梁竖向位移、主塔塔偏四个指标的最大反应位置；利用无线加速度传感器对吊杆面外振动基频进行测试,探讨吊索力计算的影响因素和吊杆内力计算方法;通过特征值分析,确定了只对大桥主跨主梁竖向振动模态进行监测的方案,提出了利用Fisher信息矩阵和MAC矩阵的联合算法对主梁主跨竖向振动测点进行优化的方法。3、运营期独塔自锚式悬索桥主要构件响应规律分析利用阶段性监测数据,对主梁应变、主梁竖向位移、主缆轴力、吊索力在运营期的响应规律进行了分析,结果表明：主梁应变和周围环境温度成明显的正相关；四个季度内主梁竖向位移测点变化幅值很小,上下游主梁同一截面变化趋于一致；主缆轴力在四个季度的监测中保持平稳；吊索力受温度影响较为明显,温度低的季节,吊索力计算结果误差较大。4、基于模糊层次分析的综合状态评估方法研究为了更加有效的反映主要评估构件的不同影响,引入成对模糊判断矩阵,并利用模拟求解法求解权重向量；通过对顶层评价指标进行分类,引入量纲为“1”化处理方法,使各指标间具有了可比性；引入变加权系数概念,考虑了当评价指标出现严重缺陷时对整体评估结果的影响；在以上分析基础上,建立了考虑主塔、主缆、吊杆、加劲梁、桥塔基础和附属设施影响的江心洲大桥多层次多目标综合评估模型,并实现了变权模糊层次分析法在江心洲大桥实际状态评估中的有效应用。
[Abstract]:As a new type of bridge, single-tower self-anchored suspension bridge has been developed rapidly in recent ten years at home and abroad. Therefore, based on the background of Nanjing Jiangxinzhou Bridge, this paper makes a systematic study on monitoring and state evaluation of single-tower self-anchored suspension bridge during operation. The main research work and achievements are reflected in the following aspects: 1. The influence factors and monitoring contents of self-anchored suspension bridge structure are analyzed. According to the structural characteristics of self-anchored suspension bridge, the main structural parts, including cable suspension system, are analyzed. Main tower structure, stiffened beam structure safety influence factors, on the basis of structural safety factors analysis, Determination of self-anchored suspension bridge safety monitoring content and regular detection content. 2. The corresponding monitoring method for each monitoring content in operation period is studied for Nanjing Jiangxinzhou Bridge. Based on the analysis of moving load, considering the most unfavorable combination of loads, the maximum response position of the four indexes of main cable internal force, main beam stress, main beam vertical displacement and main tower deviation is determined. By using wireless acceleration sensor to test the fundamental frequency of out-of-plane vibration of the boom, the factors affecting the calculation of the slings force and the calculation method of the internal force of the suspender are discussed. It is determined that only the vertical vibration modes of the main girder of the bridge should be monitored. The method of optimizing the vertical vibration measuring point of main girder by using the joint algorithm of Fisher information matrix and MAC matrix is put forward. The response law of main component of self-anchored suspension bridge with single tower in operation period is analyzed and the strain of main beam is analyzed by using the monitoring data. The vertical displacement of the main beam, the axial force of the main cable and the force of the sling are analyzed in the operation period. The results show that the strain of the main beam is positively correlated with the ambient temperature, and the amplitude of the measuring point of the vertical displacement of the main beam is very small in four quarters. The variation of the same section of the upper and lower main girder tends to be the same; the axial force of the main cable remains stable during the four quarters of monitoring; the sling force is affected more obviously by the temperature, and the temperature is low in the season, The error of slings force calculation results is large. 4. In order to reflect the different effects of main evaluation components more effectively, the comprehensive state evaluation method based on fuzzy analytic hierarchy process (FAHP) is introduced into a pair of fuzzy judgment matrix. The weight vector is solved by using the simulation solution method; by classifying the top evaluation index, the dimensionality is introduced as "1", so that the indexes are comparable, and the concept of variable weighting coefficient is introduced. The influence of the evaluation index on the overall evaluation results is considered when there are serious defects in the evaluation index. On the basis of the above analysis, the main tower, main cable, suspender rod, stiffening beam are considered. The multi-level and multi-objective comprehensive evaluation model of Jiangxinzhou Bridge under the influence of tower foundation and ancillary facilities has been developed, and the effective application of variable weight Fuzzy Analytic hierarchy process (FAHP) in the actual state assessment of Jiangxinzhou Bridge has been realized.
【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】：U446;U448.25

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