摘要
四川省泸定县冷竹关沟两岸属于高陡斜坡,距2022年5月20日汉源M_(S)4.8地震震中52 km。基于冷竹关沟监测剖面上安置的4台强震仪对汉源M_(S)4.8地震的监测数据,分析了高陡斜坡上的地震波响应规律,并与前人研究成果对比,结果显示:(1)斜坡对此次地震的地震波放大效应在水平南北向最为显著,右岸半岛状山梁处的放大作用强于左岸浑厚山体,且随着高程的增加场地的放大作用逐渐增大;(2)斜坡右岸的地震动卓越频率为2—6 Hz,左岸主要分布在7—13 Hz,冷竹关沟高陡斜坡的地震动卓越频率在半岛状山梁部位以特低频为主,在浑厚山体斜坡以中低频为主,在未来可能发生的地震中,斜坡更容易与卓越频率在此范围内的地震动记录发生共振作用,以致坡体地震动响应强烈;(3)冷竹关沟高陡斜坡存在地震波背坡效应,同时该处斜坡对地震波的放大效应还受到微地形的控制,地震波在右岸坡顶凸起地形处能量最为强烈,右岸斜坡坡顶在地震波经过时更容易发生崩塌等次生灾害。
The northwest region of Sichuan is located in the southeastern part of the Qinghai Tibet Plateau,with well-developed mountain and canyon landforms and frequent earthquakes.It belongs to a seismically active mountainous region.Both sides of Lengzhuguan gully in Luding County,Sichuan Province belong to high and steep slopes,which are representative in the high mountain and canyon areas of western China.At the same time,Lengzhuguan gully is located in the transitional zone from the Qinghai Tibet Plateau to the Sichuan Basin,as well as the“Y” shaped area where the southwest end of the Longmenshan Fault Zone intersects with the Xianshui River Fault Zone,The tectonic activity in the area is strong,and the setting up strong earthquake monitoring profiles here can effectively monitor seismic wave information in the nearby area.These seismic data can be used to effectively analyze the seismic dynamic characteristics of the terrain in the area.On May 20,2022,an M_(S)4.8 earthquake occurred in Hanyuan County,Sichuan Province,with the epicenter 52 km away from the Lengzhuguan gully monitoring profile.This earthquake triggered the installation of four strong seismic instruments on the Lengzhuguan gully monitoring profile,and obtained seismic wave time history data of the Hanyuan M_(S)4.8 earthquake.To study the seismic wave response law on high and steep slopes,the peak acceleration and Arias intensity characteristics of this seismic wave were analyzed through the time history curve of monitoring points,Obtain the peak acceleration amplification coefficient and Arias intensity amplification coefficient of different elevation monitoring points.After processing and analyzing the acceleration time-history curve(including filtering and correction),we have calculated the three-component seismic acceleration response spectra under different damping ratios(5%,10%,20%).Studying the terrain amplification effect of seismic waves in different parts of the slope,and comparing and analyzing with previous research results based on the
作者
唐涛
王运生
吴昊宸
刘世成
冯卓
詹明斌
Tang Tao;Wang Yunsheng;Wu Haochen;Liu Shicheng;Feng Zhuo;Zhan Mingbin(State Key Laboratory of Geohazard and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China;College of Environment and Civil Engineering,Chengdu University of Technology,Chengdu 610059,China)
出处
《地震学报》
CSCD
北大核心
2024年第3期502-513,共12页
Acta Seismologica Sinica
基金
国家自然科学基金(41877235)
国家重点研发计划(2017YFC1501000)
国家创新研究群体科学基金(41521002)
地质灾害防治与地质环境保护国家重点实验室自主课题(SKLGP2015Z001)共同资助。
