摘要
石窟多开凿于山间、崖壁等地质条件复杂的区域,易被地震破坏。厘清石窟崖体的动力响应特征,进行针对性的抗震、减震加固,可以有效减轻地震对石窟的破坏。为揭示麦积山石窟崖体的地形效应,基于微震监测数据,通过传统的傅里叶谱比法、H/V谱比法和瞬时极化偏振法(HVIP),研究石窟崖体场地动力响应特征与石窟崖体地形效应的方向性。结果表明:麦积山石窟场地放大系数、传统傅里叶谱比法比值和H/V值均随着高程的增加而增大;加速度峰值放大系数为NS向最大,EW向次之,UD向最小;石窟崖体的卓越频率在1~5 Hz之间;石窟崖体存在着明显的方向性共振现象,地震波在震源方向上表现为放大效应,在山体走向上表现为衰减效应。在石窟崖体场地中,传统傅里叶谱比法能较好地反映卓越频率,H/V值能客观准确地表现出石窟崖体的地层结构。该研究可为依托场地地震响应开展石窟抗震和减震工作提供参考。
Grottoes,often constructed in geologically complex mountainous or cliff areas,are prone to earthquake damage.Understanding the dynamic response characteristics of grotto cliffs and implementing targeted seismic resistance and damping reinforcement can effectively mitigate earthquake-induced damage.To investigate the topographic effects of the cliff at the Majiishan Grottoes,this study analyzed the dynamic response characteristics and directionality of topographic effects using microseismic monitoring data through three methods:the traditional Fourier spectral ratio,the horizontal-to-vertical(H/V)spectral ratio,and the horizontal-to-vertical instantaneous polarization methods.Results indicate that amplification factors at the Majiishan Grottoes site,including traditional Fourier spectral ratios and H/V values,increase with elevation.Peak acceleration amplification is highest in the NS direction,followed by the EW direction,and lowest in the UD direction.The predominant frequencies of the cliff range from 1 to 5 Hz.Notable directional resonance phenomena in the cliff are observed,with seismic waves exhibiting amplification toward the seismic source and attenuation along the strike of the mountain.The traditional Fourier spectral ratio method effectively reflects predominant frequencies,while H/V values accurately characterize the stratigraphic structure of the cliff body.This study provides a reference for implementing seismic resistance and damping measures based on site-specific seismic responses.
作者
郭鼎楠
刘琨
何小龙
徐博凯
田文通
路富存
杨博
GUO Dingnan;LIU Kun;HE Xiaolong;XU Bokai;TIAN Wentong;LU Fucun;YANG Bo(Lanzhou Institute of Seismology,CEA,Lanzhou 730000,Gansu,China;Key Laboratory of Loess Earthquake Engineering of CEA&Gansu Province,Lanzhou 730000,Gansu,China;Gansu Earthquake Agency,Lanzhou 730000,Gansu,China;Maiji Mountain Grottoes Art Institute,Tianshui 741000,Gansu,China;School of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,Gansu,China)
出处
《地震工程学报》
北大核心
2025年第4期979-990,共12页
China Earthquake Engineering Journal
基金
2024陇原青年创新创业人才项目(2024QNTD51)
中国地震局地震科技星火计划项目(XH24043A)
国家自然科学基金联合基金项目(U22A205999)
甘肃省敦煌文物保护研究中心开放课题(GDW2021YB01)。
关键词
麦积山石窟
微震监测
地形效应
HVSR法
HVIP法
Majiishan Grottoes
microseismic monitoring
topographic effects
horizontal-to-vertical spectral ratio(HVSR)method
horizontal-to-vertical instantaneous polarization(HVIP)method
