地脉动空间自相关方法反演浅层S波速度结构  

Inversion of S-wave velocity structure near the surface by spatial autocorrelation technique of microtremors

作　　者：刘庆华[1] 鲁来玉[1] 何正勤[1] 胡刚[1] 王凯明[1] 龚艳 

机构地区：[1]中国地震局地球物理研究所,中国北京100081 [2]通海县防震减灾局,中国云南玉溪652799

出　　处：《地震学报》2016年第1期86-95,157,共10页Acta Seismologica Sinica

基　　金：国家自然科学基金(41174041)资助

摘　　要：在近地表地球物理领域,基于地脉动(或称背景噪声)提取的面波频散曲线反演地下S波速度结构是一种简单经济的工程勘察方法.本文基于地脉动的空间自相关方法对一个微型台阵观测的背景噪声记录进行处理,介绍了一种简单易行的提取频散曲线的数据处理方法,获得了6.7—23Hz频段的可靠频散曲线;通过对该观测频散曲线与预测模型的频散曲线进行拟合,反演得到S波速度结构.结果表明,该速度结构与钻孔直接测试的结果相吻合.In the field of near surface geophysics, the inversion for the velocity structure based on the dispersion of surface waves extracted by spatial auto- correlation （SPAC） of microtremors is a simple and reliable geoteehnique scheme. This paper deals with the ambient seismic noise recorded by a circular array, and introduces a simple method to extract the dispersion curve of surface wave by processing the SPAC coefficients properly. The reliable dispersion curves in the frequency range of 6.7--23 Hz are extracted. The S-wave velocity structure is obtained by fitting the observed dispersion curves with predicted ones. The structure by inversion agrees well with that obtained by drilling test under the array.

关 键 词：地脉动 空间自相关(SPAC)方法 频散曲线 面波反演 S波速度结构 

分 类 号：P315.31[天文地球—地震学]