一种可模态分离的高分辨率频率-波数法及其工程应用  

A Mode-separable High-resolution Frequency-wavenumber Method and Its Engineering Application

作　　者：周晓[1] 岳子冲 刘宏岳[2] 郑金伙[2] 化希瑞[3] 刘铁[3] 牟新刚[1] Zhou Xiao;Yue Zichong;Liu Hongyue;Zheng Jinhuo;Hua Xirui;Liu Tie;Mou Xingang(School of Mechanical and Electronic Engineering,Wuhan University of Technology,Wuhan 430070,China;Fujian Provincial Institute of Architectural Design and Research,Fuzhou 350001,China;China Railway Siyuan Survey and Design Group Co.Ltd,Wuhan 430063,China)

机构地区：[1]武汉理工大学机电工程学院,武汉430070 [2]福建省建筑设计研究院,福州350001 [3]中铁第四勘察设计院集团有限公司,武汉430063

出　　处：《中国地震》2024年第2期484-502,共19页Earthquake Research in China

基　　金：湖北省重点研发计划项目(2021BAA050)资助。

摘　　要：高分辨率频率-波数法是通过计算F-K谱从能量角度获取主导表面波频散信息的一种常用方法。然而,由于高模态瑞利波的能量通常低于基阶波的能量,因此难以分离多模态频散信息。本文通过建立多模态瑞利波模型,并讨论其相速度、波数和能量特性,提出一种可模态分离的高分辨率频率-波数法。通过增强F-K谱上的高模态能量,提取其多模态能量的局部极值,进而得到相速度点,对所有相速度点进行概率分布并拟合,得到多模态频散曲线。工程应用表明,改进的高分辨率频率-波数法能够较好地还原多模态瑞利波信息,通过对提取的多模态频散曲线进行联合反演,可以得到与工程钻孔结果匹配较好的剪切波速度结构。The high-resolution frequency-wavenumber method is a frequently used method to obtain the dispersion information of the dominant surface waves from the perspective of energy by calculating the F-K spectra.However,since the energy of the higher-mode Rayleigh waves is usually lower than that of the fundamental mode,it is often difficult to separate the multi-mode dispersion information.In this paper,an improved high-resolution frequency-wavenumber method for mode separation which establishes a multi-mode Rayleigh waves model is proposed,and its characteristics of phase velocity,wavenumber and energy is discussed.By enhancing the higher-mode energy on the F-K spectra,extracting its local extremums of multi-mode energy to get the phase velocity points,and fitting the probability distribution of all phase velocity points,the multi-mode dispersion curves are extracted.The engineering application shows that the improved method can better restore the information of multi-mode Rayleigh waves,and through the joint inversion of the extracted multi-mode dispersion curves,it is capable to match the shear wave velocity structure with the engineering borehole results.

关 键 词：频率-波数法 微动勘探 频散曲线 多模态面波 工程应用 

分 类 号：P315[天文地球—地震学]