混凝土坝累积损伤流激响应特性及体征判诊方法

According to the characteristics of flow-induced vibration and dynamic accumulated damage of the concrete dam during operation period, previous research has shown that not only the discharge excitation is an important reason for crack’s propagation in dam structure, the behavioral data of dam damage is also a main basis for diagnosis of the dam safety. However, at present system study on health diagnosis of structure performance which introduces static and dynamic response information of dam is not enough. A strategy combining theoretical analysis, numerical simulation, test method and in-situ observation will be used to study the de-noising, decomposition and reconstruction of characterization information of the dam’s service condition under ambient excitation, construct a data mining method of the vibration response signal on concrete dam, and reveal the internal connection between the dam’s dynamic fingerprint and its dependent factors. Further, by the analysis of the mechanism of flow-induced response for concrete dam, an analysis model of the dam’s static and dynamic response considering cumulative damage effect and a method for determining characteristic parameters can be constructed to reveal the behavior characteristics of macro mechanical response during operation period of concrete dam. Based on the redundancy and the time-variability of the diagnostic system, the fusion layer by layer, membership weighting and the cloud computing technology of ladder index can be explored, diagnosis method of judging safety states of concrete dam introducing static and dynamic monitoring data can be studied and put forward to provide a theoretical basis and decision support for long-term service and operation management of concrete dam.

针对运行环境下混凝土坝坝身流激振动及动态累积损伤特性，前期研究表明，泄流激励是诱发高坝结构起裂及其扩展的重要原因，坝体损伤劣化体征信息又是判诊大坝性态安全的主要依据，目前有关融合大坝静动力响应信息的结构性能健康诊断的系统研究相对较少。本项目拟采用理论分析、数值仿真、模型试验与原型观测相结合的研究方法，研究环境激励下大坝服役性态表征信息的消噪、分解与重构，构建混凝土坝激振响应信号的数据挖掘方法，揭示坝体动力指纹与其依存诸因素间的内在关联；更进一步，通过分析混凝土坝流激响应机制，建立考虑损伤累积效应的坝体静动力响应分析模型和特征参量的确定方法，以期揭示运行期混凝土坝宏观力学响应行为特征；基于搭建体系的冗余性及其经时变异性特点，探究梯阶指标的逐层融合、隶属赋权及组合云计算技术，研究并提出融合静动力监测数据的混凝土坝体征健康判诊方法，以此为混凝土坝长效服役和运行管理提供理论依据与决策支持。

由于目前水工模型试验结果因高速多相流及工程运行工况与物理试验存在一定偏差，难以考量运行期混凝土坝受高水头及波浪拍振等静动荷载的累积损伤及结构初始缺陷，科学而又准确地通过外部荷载激励无损识别坝体的结构参数和探究大坝服役性态演化特性并作出安全诊断是坝工领域的一个重要问题。申请人拟采用理论分析、原型观测、数值模拟、模型试验相结合的研究方法开展了混凝土坝累积损伤流激响应特性及体征判诊方法研究。依据泄流结构振动响应的形成机制，开展对振动响应信号的分析处理，提取并识别坝体在外荷载激励下的坝体模态参数；通过大坝环境变量及结构模态参数之间存在的隐式关系，采用流固耦合分析法构建坝体—库水三维耦合有限元修正模型，以探究复合因素作用下混凝土坝力学性能演化规律；结合试验数据和大坝动态监测信息，构建基于静动力面板数据的混凝土坝整体运行性状安全综合诊断体系，提出在单位约束条件下基于G1法与熵权法的主客观组合赋权路径，发展了融合多源时空信息的混凝土坝服役性态综合判诊方法，为相关水工结构运行性态评价提供理论与技术支持。