【作者】 徐文胜；

【导师】 朱宏平；

【作者基本信息】 华中科技大学 ， 结构工程， 2013， 博士

【摘要】 确保桥梁结构的安全，需要在不同阶段对结构的安全进行监控、监测和评估。首先，在桥梁施工阶段，要对桥梁施工实施全程监督与控制，保证施工过程中结构处于安全状态，成桥状态桥面线形与受力状态符合设计要求。然后，对于新建桥梁，一来要通过成桥通车鉴定试验来验证桥梁的施工质量，二来可以建立可用于损伤识别和健康监测的基准有限元模型。最后，对于在役桥梁，要对桥梁结构的整体行为的进行实时监测，通过测定其关键性能指标，获取反映结构状况的信息，对其健康状况进行评估。虽然国内外在桥梁结构安全评估领域开展了不少研究工作，已有许多处理方法和研究成果，但还有许多关键问题或难点没有得到很好地解决，比如，对严寒地区大跨高墩连续刚构桥梁进行系统安全评估的研究成果不多。本论文就是基于这样的背景，在国家杰出青年科学基金项目（No.50925828）资助下，结合小沙湾黄河特大桥工程实际，旨在从桥梁施工阶段开始，到桥梁的实际运营阶段，对桥梁安全进行监控监测，然后基于监测数据对桥梁结构的安全性进行评估，确保结构处在一个安全的状态。重点研究了大跨度桥梁施工监控、大跨度桥梁基准有限元模型的建立和大跨度桥梁结构健康监测。研究结果可广泛应用于桥梁结构的施工监控、损伤识别、健康监测以及承载力评定，具有较大的理论意义和工程实用价值。本论文在如下几方面进行了理论、数值与试验研究，并取得了一些研究成果：(1)对黄河小沙湾特大桥进行了施工监控。首先介绍了施工监控的目的、原则和方法，并制定了施工监控的实施方案，对桥梁施工过程进行了全程监控，从线形和应力监控结果可以看出，小沙湾黄河特大桥上部结构质量符合规范要求，内力和线形误差均在可控范围内。(2)建立了小沙湾黄河大桥的基准有限元模型。通过实桥静动力测试获得桥梁真实特性。利用优化算法，以成桥动力特性实测结果为目标，对小沙湾黄河大桥的初始有限元模型进行了模型修正。修正后的小沙湾黄河大桥有限元模型的动力特性与实测值基本一致，表明该修正模型能够代表小沙湾黄河大桥的结构特性，可以作为后续健康监测以及损伤识别的基准模型。(3)建立了小沙湾黄河大桥的健康监测系统，并利用该系统对小沙湾黄河大桥成功监测至今。监测系统记录了桥梁结构的形变、动力响应情况，均满足结构设计的要求，监测系统的建立有助于为大桥的日常维护提供可靠的指导和判断。小沙湾黄河特大桥的各测点位移均较小，桥梁的运营处于安全状态。(4)利用建立的小沙湾黄河大桥健康监测系统获取的前两年监测数据，确定了小沙湾黄河大桥的健康监测通常限值。利用建立的小沙湾黄河大桥基准有限元模型，确定了小沙湾黄河大桥的安全限值。为小沙湾黄河大桥后续的健康监测及结构安全性评估提供了一个判定指标。更多还原

【Abstract】 To guarantee the safety of bridge structure, it is essential to control, monitor andassess the safety of biridge structure at different stages. Firstly, during bridge construction,it is necessary to inspect and control the bridge construction throughout the the wholecourse to ensure the safe condition of structure in different stages, and the line shape andstress condition after the completion. Secondly, for the newly constructed bridges, it isessential to verify the construction quality and build the baseline finite element model forlater damage identification and health monitoring through the test for open to traffic. Inthe end, for existing bridge, it is also necessary to monitor the real-time overall behaviorof bridge, aquire the information that reflects the structure condition through measure itsKey Performance Indicators and assess its health condition.Though many research works are carried out home and abroad, and there are manyprocess methods and research findings about bridge safety assessment, many keyproblems or difficulties have not been solved, such as there is few research results for thelong-span high-pier continuous rigid frame bridge in cold regions.. Based on the researchbackground and sponsored by supported by a grant from National Science Fund forDistinguished Young Scholars （No.50925828）,combined with the engineering practicesof Xiaoshawan Huanghe Super Major Bridge, this dissertation aims to study a few keytechniques of the assessment of bridge safety from the construction phase to the actualoperational phase, control and monitor the bridge safety, gurantee its condition all the time,the construction control for long-span bridge, the setup of baseline finite element modellong-span bridge and health monitoring for long-span bridge are mainly investigated. Theresults of the dissertation can be used in the practice of bridge structures for constructioncontrol, damage identification, health monitoring and bearing capacity evaluation and theapplication is significant theoretically and practically.In this dissertation, following aspects are studied theoretically, numerically andexperimentally, and some results are achieved:(1) The construction control is carried through successfully for XiaoshawanHuanghe Super Major Bridge. The aim, principle and method of construction control are introduced, and the implementation plan is set up. The the construction process arecontrolled all the time. From the results of line shape and stress, it can be seen that thequality of superstructure meets the requirements of codes, and the errors of internal forceand ling shape are all manageable.(2) The baseline finite element model of Xiaoshawan Huanghe Super Major Bridge isset up. Firstly, the basic theory of optimization algorithm is introduced; secondly, the theinitial finite element model is set up according to the design drawings and based on theanalytical results the in-situ vibration testing is carried out; In the end, the baseline finiteelement model is set up based on optimization algorithm and model updating. Thebaseline finite element model can reflect the dynamic behavior very well and can be usedin the future health monitoring.(3) The real-time health monitoring is carried out successfully. The monitoringsystem records the displacement, stress and temperature of bridge structure under differentcondition, the setup of monitoring system is helpful for the routine maintenance of bridge.From the available results, the displacement and strain at the survey points are little andvary regularly with the variation of air temperature, the dynamic characteristics variesvery little and the variation of bridge deck elevation is also very small. From all the resultsit can be concluded that the bridge is healthy and in a safe operation condition.(4) Based on the data drawn from the Health Mornitoring System of XiaoshawanHuanghe Super Major Bridge, the normal limit values were determined. And the safetythreshold values were alsl determined based on the baseline FE model. All these valuescan be worked as the decision indicators for the health monitoring and structural safetyassessment of Xiaoshawan Huanghe Super Major Bridge.更多还原