摘要
河北平原地裂缝分布广泛、致灾严重,给当地工程建设和人民生活造成了严重影响。目前对于河北平原地裂缝的研究主要是发育特征、成因机理以及分布等方面,对该区域场地动力特性的研究不足。为讨论河北平原地裂缝对场地动力响应的影响,分别选取该地区具有代表性的地裂缝(高丽营地裂缝和隆尧地裂缝(构造成因)、大名地裂缝(古河道成因)、唐山地裂缝(地震成因))进行野外地脉动测试,并通过傅里叶谱分析、反应谱分析和Arias烈度分析,揭示了不同类型地裂缝场地的动力响应特征。结果表明,地裂缝对场地卓越频率和卓越周期的影响较小,但对场地动力响应强度的影响较大。在地裂缝附近区域具有放大效应,上盘放大倍数达到2.2~2.7,下盘放大倍数达到1.7~2.4,并随着与地裂缝距离的增大逐渐衰减,一定距离后趋于平稳,且活动性更强的上盘的放大效应更明显。不同类型地裂缝对场地动力响应的影响趋势基本一致,但影响范围不同:构造地裂缝场地的放大效应影响范围最大,约24 m,地震地裂缝次之,约22 m,古河道地裂缝最小,约20 m。综合考虑河北平原地裂缝对场地影响范围:上盘约24 m,下盘约20 m。场地放大效应及其影响范围可以为河北平原地裂缝场地工程结构的合理抗震设防提供依据。
Ground fissures in the Hebei Plain are widely distributed and cause severe disasters,seriously impacting local engineering construction and people’s life.The research on ground fissures in the Hebei Plain focuses mainly on the de-velopment characteristics,genesis mechanism,and distribution.However,there is little research on the dynamic charac-teristics of the site in this area.In order to study the influence of ground fissures on the dynamic response of the site in the Hebei Plain,this study conducted microtremor testing on typical earth fissures caused by tectonics,earthquakes,and ancient rivers.It determined the dynamic response characteristics of earth fissure sites of different origins by the Fourier amplitude spectrum,response spectrum,and Arias intensity.The results show that the ground fissures have a small im-pact on the predominant frequency and predominant period,but have a great influence on the dynamic response strength of the site.Furthermore,the dynamic response has an amplification effect near the fissure,which increases to 2.2-2.7 times on the hanging side and 1.7-2.4 times on the heading side.It gradually declines with the increase of the distance from the fissure and finally stabilizes.The amplification effect is greater on the hanging side.The influence of different types of ground fissures on the dynamic response of the site is basically the same,but the influence range is different.The tectonic fissure has the largest amplification effect,about 24 m,the seismic fissure is the second,about 22 m,and the paleochannel fissure is the smallest,about 20 m.After full consideration,the ground fissures influence the dynamic response of the site out to about 24 m on the hanging side and 20 m on the heading side.The amplification effect and the range of influence can provide a reasonable seismic fortification basis for the engineering structure of the ground fissure site.
作者
崔思颖
邓亚虹
曹歌
于双瑞
慕焕东
李艳杰
CUI Siying;DENG Yahong;CAO Ge;YU Shuangrui;MU Huandong;LI Yanjie(School of Geological Engineering and Geomatics,Chang’an University,Xi’an 710054,China;Key Laboratory of Mine Geological Hazards Mechanism and Control,Chang’an University,Xi’an 710054,China;Institute of Geotechnical Engineering,Xi’an University of Technology,Xi’an 710048,China)
出处
《煤田地质与勘探》
CAS
CSCD
北大核心
2022年第6期81-93,共13页
Coal Geology & Exploration
基金
国家自然科学基金项目(41772275)
陕西省自然科学基础研究计划项目(2022JQ-289)
陕西省教育厅专项科研计划项目(20JK0801)。
关键词
地裂缝场地
动力响应
地脉动
放大效应
影响范围
ground fissure site
dynamic response
microtremor
amplification effect
influence range
