基于地震记录的高拱坝模态识别  

Modal identification of an arch dam with seismic records

作　　者：王海波[1] 许亮华[1] 廖建新 李德玉[1] WANG Haibo;XU Lianghua;LIAO JianXin;LI Deyu(China Institute of Water Resource and Hydropower Research,Beijing 100048,China;China Three Gorges Projects Development Co.,Ltd.,Chengdu 610000,China)

机构地区：[1]中国水利水电科学研究院,北京100048 [2]中国三峡建设管理有限公司,四川成都610000

出　　处：《中国水利水电科学研究院学报》2020年第4期241-247,共7页Journal of China Institute of Water Resources and Hydropower Research

基　　金：中国长江三峡集团公司科研项目(XLD/2115)。

摘　　要：溪洛渡拱坝坝体及下游自由场共计安装了27台三向强震记录仪。自强震监测系统运行以来,近坝区域发生过几次有感地震。2018年5月8日云南昭通市永善县3.8级地震,大坝记录到坝顶最大响应加速度8.62 gal。本研究利用此次强震记录,基于时域模态分析技术,对溪洛渡拱坝的模态参数进行了识别。在地震对应的上下游水位情况下,溪洛渡拱坝的基频为1.19 Hz,对应的一阶振型为反对称振型,二阶频率1.50 Hz,对应二阶振型为正对称振型;第三阶频率1.67 Hz,对应振型为反对称振型,更高阶的2.33 Hz和2.60 Hz模态对应的高阶振型有明显拐点变化。Xiluodu is the 2^nd largest hydropower station of China,its arch dam is equipped with 27 strong seismometers for seismic monitoring.Several felt earthquakes happened near the dam site region since the monitoring system was put into operation in 2016.The largest acceleration recorded on the dam top was 8.62gal due to the earthquake dated May 8,2018 with a Richter magnitude of M3.8.Modal identification of the dam was carried out with the acceleration recorders on the dam of the earthquake based time do⁃main modal identification technique.The results indicate that the first vibration mode is anti-symmetric in arch direction with a characteristic frequency of 1.19Hz,the second one is symmetric at 1.50Hz,and the third one is again anti-symmetric at 1.67Hz.In the higher modes of 2.33Hz and 2.60Hz,the turning points are obvious.

关 键 词：溪洛渡拱坝 模态参数 系统识别 强震记录 

分 类 号：TV31[水利工程—水工结构工程]