摘要
基于北川沈家包斜坡场地地脉动数据,采用水平与垂直谱比(horizontal-to-vertical spectral ratio,HVSR)法,探究了斜坡场地地震效应特征。结果表明:①沈家包斜坡场地HVSR曲线以双峰型或多峰型为主,土层峰值频率集中于1.39~3.90 Hz,与峰值频率对应的放大系数位于1.89~3.80,展现出了较为明显的局部地形放大效应;②沈家包斜坡坡顶、坡腰处地脉动的优势方向较易判别,分别为30°~80°和110°~160°,当某一区域内多个测点峰值频率趋于一致时,其方向性分布也较为集中,揭示出地层结构对场地土层方向性特征的控制作用;③沈家包斜坡节理产状优势方向为60°~80°,与斜坡坡顶地脉动优势方向(30°~80°)吻合较好,但与斜坡走向(110°)呈锐角相交,对比王家岩滑坡场地地震效应特征,沈家包斜坡前缘抗滑桩的布设是阻挡斜坡失稳滑动的重要因素。研究结果为探究斜坡场地地震效应和斜坡灾害的防治提供了参考。
Based on the microtremor data of Shenjiabao slope site in Beichuan,the horizontal-to-vertical spectral ratio(HVSR)method was used to explore the seismic effect characteristics of slope site.The results show that:①The HVSR curve of Shenjiabao slope site is mainly bimodal or multimodal.The peak frequency of the stratum is concentrated in 1.39-3.90 Hz,and the amplification coefficient corresponding to the peak frequency is between 1.89 and 3.80,showing a relatively obvious local topographic amplification effect.②The dominant directions of microtremors at the top and waist of Shenjiabao slope are easy to distinguish,which are 30°-80°and 110°-160°respectively.When the peak frequency of multiple measuring points in a certain area tends to be consistent,the directional distribution is also more concentrated,which reveals the control effect of the underlying stratum structure change on the directional characteristics of the site soil layer.③The dominant direction of the joint occurrence of the Shenjiabao slope is 60°-80°,which is in good agreement with the dominant direction of the ground pulsation at the top of the slope(30°-80°),but it intersects with the slope strike(110°)at an acute angle.Compared with the seismic effect characteristics of the Wangjiayan landslide site,the layout of the anti-slide pile at the front edge of the Shenjiabao slope is an important factor in blocking the formation of the landslide.The research results provide a reference for exploring the seismic effect of slope sites and the prevention and control of slope disasters.
作者
李孝波
王天虎
王怀强
柳耀阔
席书衡
赵扬
LI Xiaobo;WANG Tianhu;WANG Huaiqiang;LIU Yaokuo;XI Shuheng;ZHAO Yang(Institute of Disaster Prevention,Sanhe 065201,China;Hebei Key Laboratory of Earthquake Disaster Prevention and Risk Assessment,Sanhe 065201,China)
出处
《振动与冲击》
2025年第8期241-250,共10页
Journal of Vibration and Shock
基金
地震科技星火计划(XH23066A)
国家自然科学基金(U1939209,51808118)。
关键词
沈家包斜坡
地脉动
水平与垂直谱比(HVSR)法
峰值频率
方向性特征
Shenjiabao slope
microtremor
horizontal-to-vertical spectral ratio(HVSR)method
peak frequency
direction characteristic
作者简介
第一作者:李孝波,男,博士,教授,1985年生,E-mail:lixiaobo@cidp.edu.cn。
