大岗山高拱坝地震动力响应特征分析——以泸定6.8级地震为例

Seismic Dynamic Response Characteristics of Dagangshan High Arch Dam:Case Study on Luding Ms 6.8 Earthquake

为了探究2022年9月5日四川甘孜州泸定县6.8级地震对大岗山高拱坝的影响,根据坝体及坝基上布置的由21台强震仪组成的强震监测系统监测记录,对泸定地震强震监测数据进行了时域和频域分析,总结了大岗山高拱坝在泸定地震中的动力响应规律。分析结果表明:泸定地震时坝顶与两岸坝肩的位移与加速度较大,加速度峰值最大为576.6 cm/s~2,位于坝顶6^(#)坝段;大岗山高拱坝对频率范围为0.5~8 Hz的地震动响应最为明显;坝体高程对地震动响应具有放大效应,且顺河向加速度峰值放大该效应最明显。震后大坝运行状态稳定,整体受地震影响较小,但坝肩及两岸边坡处需引起重视。研究成果可为类似拱坝的安全运行提供参考。

The aim of this research is to explore the impact of the 6.8 magnitude earthquake in Luding County,Ganzi Prefecture of Sichuan Province on Dagangshan High Arch Dam on September 5,2022.According to the monitoring data of 21 earthquake sensors installed across the dam body and its foundation,we analyzed the time and frequency domains of the seismic recordings from the Luding earthquake to unravel the dynamic response patterns of Dagangshan High Arch Dam during the earthquake.Findings reveal substantial displacements and accelerations along the dam crest and the abutments on both sides.Notably,the highest recorded acceleration peak,reaching 576.6 cm/s~2,was found at the No.6 dam section atop the crest.The seismic impact on Dagangshan High Arch Dam manifests prominently within the frequency spectrum of 0.5 to 8 Hz.Moreover,the dam’s towering stature accentuates ground motion response,particularly amplifying peak accelerations along the riverbanks.Post-earthquake assessment indicates the dam’s operational stability with minimal impact on its overall integrity.However,vigilance is warranted for the dam abutments and adjacent slopes,necessitating meticulous observation and maintenance measures.