摘要
采用实测地震记录来识别高土石坝的模态参数是进行大坝动力特性研究的一种可行的方式。根据地震中坝体监测点记录的数据构建协方差驱动的随机子空间模型(stochastic subspace identification,SSI),通过构造多个不同维度的Hankel矩阵来形成稳定图,可以很好地剔除虚假模态,形成较清晰的稳定轴,采用谱系聚类的筛选方法,不仅可以有效地识别坝体的固有频率和阻尼比,而且实现了物理模态参数的自动识别,规避了人为选择引入的误差。通过两个数值算例验证了提出的随机子空间法应用于地震数据分析的有效性和精度,并将其应用于糯扎渡心墙堆石坝的模态参数识别,获得了合理的坝体固有频率和阻尼比,表明该方法可以较好地识别出坝体的模态参数,具有很好的工程应用,可以为高土石坝抗震安全有限元分析提供一定的依据和参考。
Using the measured seismic records to identify the modal parameters of high earth-rock dams is a feasible way to study the dynamic characteristics of dams.Constructing the covariance-driven stochastic subspace identification(SSI)based on the data recorded at the monitoring points of a dam during the earthquake and the stable graph by establishing multiple Hankel matrices with different dimensions can effectively eliminate false modes.The hierarchical clustering can effectively identify the natural frequency and damping ratio of the dam,and realize the automatic identification of physical modal parameters,avoiding the errors introduced by human selection.The effectiveness and accuracy of the proposed SSI method for seismic data analysis are verified by numerical examples.It is applied to the identification of modal parameters of Nuozhadu core-wall rockfill dam,and the reasonable frequency and damping ratio are obtained,indicating that the method can identify the modal parameters of the dam well and has a good engineering application,and it can provide a certain basis and reference for the finite element analysis of seismic safety of high earth-rock dams.
作者
王茂华
迟世春
周雄雄
WANG Mao-hua;CHI Shi-chun;ZHOU Xiong-xiong(State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian 116024,China;Institute of Earthquake Engineering,School of Hydraulic Engineering,Faculty of Infrastructure Engineering,Dalian University of Technology,Dalian 116024,China;College of Water Resources and Architectural Engineering,Northwest A&F University,Yangling 712100,)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2021年第7期1279-1287,共9页
Chinese Journal of Geotechnical Engineering
基金
国家重点研发计划项目(2016YFB0201001)。
关键词
土石坝
模态参数
随机子空间
HANKEL矩阵
稳定图
谱系聚类
earth-rock dam
modal parameter
stochastic subspace identification
Hankel matrix
stabilization diagram
hierarchical clustering
