补强混凝土重力坝运行效力演变监控及安全性评估方法

According to research of efficiency evolution and security evaluation for reinforced elderly concrete dams, study by the applicant shows that it is mainly multiple forces which lead to the performance evolution of reinforced dam, and the degree of reinforcement efficiency degradation is an important basis for evaluating the structural safety. However, at present, the research on the monitoring and safety evaluation for the evolution of operational effectiveness of reinforced concrete dams is relatively less. Taking gravity dam as the object, by using the method combining theoretical analysis, numerical simulation, model test and in-situ observation, we are going to study the evolution characteristics and working mechanism of the concrete gravity dam under the multi temporal monitoring sequence, and reveal the inherent relationship between the performance evolution and its dependent factors of the gravity dam. Further on, by analyzing typical reinforcement measures of dam structure, prediction model and monitoring indexes of operational effectiveness of reinforced gravity dam are set up to reveal the evolution law of reinforcement efficiency of concrete gravity dam. Based on the high nonlinearity and parameter randomness of the performance function of reinforced gravity dam, the boundary inversion principle of dam uncertain parameters is studied, non-probabilistic time-varying reliability calculation models of unit and system of reinforced gravity dam considering parameter bound are set up, and safety assessment method of reinforced gravity dam based on time varying reliability is studied and put forward to provide theoretical basis and decision support for long service and operation management of reinforced concrete dam.

针对高龄混凝土坝病险除控效能演化规律及性态安全评估，申请者研究表明，多元合力驱动是大坝加固性能演变的主要原因，其补强效能衰退程度又是评估其结构安全度的重要依据，目前有关补强混凝土坝运行效力监控及安全性评估的系统研究相对较少。本项目以补强重力坝为对象，拟采用理论分析、数值仿真、模型试验与原位观测相结合的研究方法，研究多时域监测序列下混凝土重力坝性态演变特征及驱动机制，揭示补强重力坝性能演化与其依存诸因素间的内在关联；更进一步，通过分析大坝结构典型病险措施，建立补强重力坝运行效力预测模型及监控指标，以期揭示混凝土重力坝补强效能演化规律；基于补强重力坝功能函数的高度非线性与参数随机性，探究大坝不确定参数的界限反演原理，构建考虑参数界限的补强重力坝单元与体系非概率时变可靠度计算模型，研究并提出基于时变可靠度的补强重力坝稳定安全性评估方法，以此为补强混凝土坝长效服役和运行管理提供理论依据与决策支持。

针对高龄混凝土坝病险除控效能演化规律及性态安全评估，多元合力驱动是大坝加固性能演变的主要原因，其补强效能衰退程度又是评估其结构安全度的重要依据，目前有关补强混凝土坝运行效力监控及安全性评估的系统研究相对较少。本项目以补强重力坝为对象，分析了环境荷载变化对混凝土坝变形行为的影响效应，剖析了典型环境因素对混凝土性能劣化的作用机理。从细观尺度分析了筑坝材料性能劣化的机理，从静、动力学两个层面构建了混凝土坝结构力学演化反分析模型，提出了基于人工鱼群算法优化的混坝体混凝土弹性模量与基岩变形模了反分析模型；同时，考虑到监测数据误差与筑坝材料参数变异程度的不同，结合区间分析理论，构建了坝体与基岩物理力学参数区间反分析模型；此外，基于响应面数学模型，提出了计算模态参数和原型振动模态参数的拱坝及地基分区动弹性模量反演最优化数学模型，提出了基于敏感性分析与粒子群算法的拱坝原型动弹性模量反演方法。就混凝土坝变形预测模型方面，本项目组结合大坝原型观测资料，综合运用混沌理论，小波分析、有限元分析、支持向量机等方法，从变形监测序列残差混沌特性等角度，建立了混凝土坝变形预报统计模型和混合模型，进一步发展了混凝土坝变形预测的理论与方法。最后，在上述研究成果的基础上，本项目组归纳分析了混凝土重力坝失效路径分析与失效模式，构建了基于响应面的混凝土重力坝时变可靠性计算模型，提出了基于区间参数的重力坝单元和体系非概率可靠性分析方法与考虑除险加固影响的混凝土重力坝时变非概率可靠性分析等，据此发展了混凝土坝工作性态安全性评估方法，为补强混凝土坝长效服役和运行管理提供理论依据与决策支持。