龙羊峡重力拱坝模态识别与材料参数反演  

Modal Parameter Identification and Inverse Analysis of Longyangxia Gravity Arch Dam

作　　者：侯志英 周天宇 马宁 刘昌伟 向致谦 潘坚文[2] 王进廷[2] HOU Zhiying;ZHOU Tianyu;MA Ning;LIU Changwei;XIANG Zhiqian;PAN Jianwen;WANG Jinting(State Power Investment Corporation Qinghai Yellow River Electric Power Technology Co.,Ltd.Xining,810016,China;State Key Laboratory of Hydroscience and Engineering,Tsinghua University Beijing,100084,China;State Power Investment Corporation Limited Dam Supervision Center Xi′an,710000,China)

机构地区：[1]国家电投集团青海黄河电力技术有限责任公司,西宁810016 [2]清华大学水沙科学与水利水电工程国家重点实验室,北京100084 [3]国家电投集团大坝管理中心,西安710000

出　　处：《振动．测试与诊断》2024年第4期771-777,831,共8页Journal of Vibration,Measurement & Diagnosis

基　　金：国家自然科学基金优秀青年项目(52022047);国家自然科学基金重大项目(52192672)。

摘　　要：基于龙羊峡重力拱坝实测振动数据,利用随机子空间法进行了大坝模态参数识别,建立了坝体-地基-库水系统的三维流固耦合有限元模型。根据识别出的一阶频率,分别考虑均质地基及分层地基,反演了坝体与基岩材料参数,并通过有限元软件ABAQUS进行了大坝的动力特征分析。结果表明:龙羊峡重力拱坝的一阶频率为2.778~3.196 Hz,反演得到坝体的弹性模量约为50 GPa~52 GPa;对于均值地基,其弹性模量的反演值为30 GPa;对于分层地基,2 490 m高程以下区域的弹性模量为34 GPa;实测振动数据反演得到的坝体弹性模量和地基弹性模量高于其设计值;龙羊峡重力拱坝的前3阶振型分别为正对称、反对称与正对称,其1阶频率和2阶频率相差较大,与重力坝自振频率分布特征相似。In this paper,the modal parameters of Longyangxia gravity arch dam are identified by stochastic subspace identification method.The three-dimensional dam-foundation-reservoir finite element model of Longyangxia gravity arch dam is established,and the water pressure is simulated by using the Westergaard added mass formula.The parameters of the homogeneous foundation model and the layered foundation model of different water levels are inverted and their dynamic characteristics are analyzed.The results show that the first order frequency of Longyangxia gravity arch dam is between 2.778 Hz and 3.196 Hz.The elastic modulus of the dam body obtained by inversion using the additional mass method is about 50 GPa to 52 GPa.For the average foundation,the elastic modulus is 30 GPa;for the layered foundation,the elastic modulus in the area below the 2490 m elevation is 34 GPa.The elastic modulus of the dam body and the foundation modulus obtained by the inverse analysis are significantly larger compared to their design values.The first vibration mode is positive sym-metry,the second vibration mode is antisymmetric,and the third vibration mode is positive symmetry.The second-order frequency of the Longyangxia gravity arch dam is much bigger than the first-order frequency,which are similar to the natural vibration frequency distribution characteristics of the gravity dam.

关 键 词：龙羊峡拱坝 模态参数识别 有限元 动力特征 流固耦合 模态分析 

分 类 号：TV642.44[水利工程—水利水电工程] TH825[机械工程—仪器科学与技术]