弹性介质中瑞雷面波有限差分法正演模拟
|
摘要
为研究瑞雷面波的形成机理及传播规律,促进瑞雷面波资料处理方法的发展,本文根据弹性波方程,采用交错网格有限差分数值求解算法,对浅层各向同性弹性介质进行了包括瑞雷面波和体波在内的全波场模拟.提出了变系数吸收边界条件并将之应用于正演模拟,使边界条件的处理简单而高效,同时给出了角点的处理方法.对工程勘察中常见的连续和层状介质模型进行了模拟,获得了更加接近实际情况的地震记录.结合模拟记录,探讨了瑞雷面波的形成条件,同时讨论了震源埋深对面波能量的影响.
To study the generation mechanism and propagation rule of Rayleigh surface waves, and to accelerate the corresponding development of data processing method, the paper applies the finite-difference method with staggered grids to simulate full-wave-fields, including both Rayleigh surface wave and body waves, in shallow isotropic media based on elastic wave equations. Meanwhile, a variable coefficient absorbing boundary condition, which makes the treatment of boundary condition more simplified and more effective, is developed. Furthermore, a method to process angle points is also proposed. Simulations have been done for continuous and stratified media which are common in the field of engineering survey, and more realistic seismograms are obtained. According to the synthetic records, the condition of Rayleigh surface wave excitation is investigated, and the influence of the depth of epicenter on the energy of surface wave is discussed also.
To study the generation mechanism and propagation rule of Rayleigh surface waves, and to accelerate the corresponding development of data processing method, the paper applies the finite-difference method with staggered grids to simulate full-wave-fields, including both Rayleigh surface wave and body waves, in shallow isotropic media based on elastic wave equations. Meanwhile, a variable coefficient absorbing boundary condition, which makes the treatment of boundary condition more simplified and more effective, is developed. Furthermore, a method to process angle points is also proposed. Simulations have been done for continuous and stratified media which are common in the field of engineering survey, and more realistic seismograms are obtained. According to the synthetic records, the condition of Rayleigh surface wave excitation is investigated, and the influence of the depth of epicenter on the energy of surface wave is discussed also.
引文
[1]Haskell NA.The dispersion of surface waves on multilayered media.Bull.Seism.Soc.Am.,1953,43(1):17~34
[2]Schwab F.Surface-wave dispersion computation:Knopoff’s method.Bull.Seism.Soc.Am.,1970,60(5):1491~1520
[3]Waston HT.Anote onfast computation of Rayleigh wave dispersion in multilayered half-space.Bull.Seism.Soc.Am.,1970,60(1):161~166
[4]Abo-Zena A.Dispersion function computations for unlimitedfrequency values.Geophys.J.R.Astron.Soc.,1979,58:91~105
[5]Kennett B L N.Reflections rays and reverberations.Bull.Seism.Soc.Am.,1974,64:1685~1696
[6]Kennett B L N,Kerry NJ.Seismic waves in a Stratified halfspace.Geophys.J.R.Astron.Soc.,1979,57:557~583
[7]Sei A,Symes W.Dispersion analysis of numerical wave propagation andits computational consequences.J.Sci.Comput.,1994,10:1~27
[8]Yang D H,Liu Z R,Zhang ZJ,et al.Finite-difference modelingin two-dimensional anisotropic media using a flux-corrected transport technique.Geophys.J.Int.,2002,148:320~328
[9]李幼铭,束沛镒.层状介质中地震面波频散函数和体波广义反射系数的计算.地球物理学报,1982,25(2):130~139Li Y M,Shu P Y.On surface wave dispersion and body wave generalized reflection coefficient computations for layered media.Chinese J.Geophys.(Acta Geophysica Sinica)(in Chinese),1982,25(2):131~139
[10]Ben-Menahem A,Singh SJ.Multipolar elasticfieldinalayered half-space.Bull.Seism.Soc.Am.,1968,58:1519~1572
[11]张碧星,兰从庆,喻明等.分层介质中面波的能量分布.声学学报,1998,23(2):97~106Zhang B X,Lan C Q,Yu M,et al.Energy distribution of surface waves in stratified media.Acta Acustica(in Chinese),1998,23(2):97~106
[12]张恒山,王庆海.瑞雷面波勘探的波长解释法新探.物探与化探,1998,22(4):279~283Zhang HS,Wang Q H.A newinvestigation into interpretation of wavelength in Rayleigh wave exploration.Geophysical and Geochemical Exploration(in Chinese),1998,22(4):279~283
[13]马在田,曹景忠,王家林等著.计算地球物理学概论.上海:同济大学出版社,1997.20~27Ma Z T,Cao J Z,Wang J L,et al.Conspectus of Computational Geophysics(in Chinese).Shanghai:Tongji University Press,1997.20~27
[14]邵秀民,蓝志凌.非均匀各向同性弹性介质中地震波传播的数值模拟.地球物理学报,1995,38(增刊1):39~55Shao X M,Lan Z L.Numerical simulation of the seismic wave propagation in inhomogeneous isotropic elastic media.Chinese J.Geophys.(in Chinese),1995,38(Suppl.Ⅰ):39~55
[15]孙若昧.地震波传播有限差分模拟的人工边界问题.地球物理学进展,1996,11(3):53~58Sun R M.Artificial boundary problems in finite-difference modeling for seismic wave propagation.Progress in Geophysics(in Chinese),1996,11(3):53~58
[16]楚建伟.瞬态面波技术在冲洪积层勘察中的应用.云南地质,2004,23(1):96~103Chu J W.The application of instant surface wave technique to processing of alluviumand diluvium.Yunnan Geology(in Chinese),2004,23(1):96~103
[17]单娜琳,程志平.高阶模态面波在软弱薄层探测中的应用.桂林工学院学报,2004,24(2):155~158Shan NL,Cheng Z P.Application of high model surface waveinlow velocity thin layer.Journal of Guilin Institute of Technology(in Chinese),2004,24(2):155~158
[2]Schwab F.Surface-wave dispersion computation:Knopoff’s method.Bull.Seism.Soc.Am.,1970,60(5):1491~1520
[3]Waston HT.Anote onfast computation of Rayleigh wave dispersion in multilayered half-space.Bull.Seism.Soc.Am.,1970,60(1):161~166
[4]Abo-Zena A.Dispersion function computations for unlimitedfrequency values.Geophys.J.R.Astron.Soc.,1979,58:91~105
[5]Kennett B L N.Reflections rays and reverberations.Bull.Seism.Soc.Am.,1974,64:1685~1696
[6]Kennett B L N,Kerry NJ.Seismic waves in a Stratified halfspace.Geophys.J.R.Astron.Soc.,1979,57:557~583
[7]Sei A,Symes W.Dispersion analysis of numerical wave propagation andits computational consequences.J.Sci.Comput.,1994,10:1~27
[8]Yang D H,Liu Z R,Zhang ZJ,et al.Finite-difference modelingin two-dimensional anisotropic media using a flux-corrected transport technique.Geophys.J.Int.,2002,148:320~328
[9]李幼铭,束沛镒.层状介质中地震面波频散函数和体波广义反射系数的计算.地球物理学报,1982,25(2):130~139Li Y M,Shu P Y.On surface wave dispersion and body wave generalized reflection coefficient computations for layered media.Chinese J.Geophys.(Acta Geophysica Sinica)(in Chinese),1982,25(2):131~139
[10]Ben-Menahem A,Singh SJ.Multipolar elasticfieldinalayered half-space.Bull.Seism.Soc.Am.,1968,58:1519~1572
[11]张碧星,兰从庆,喻明等.分层介质中面波的能量分布.声学学报,1998,23(2):97~106Zhang B X,Lan C Q,Yu M,et al.Energy distribution of surface waves in stratified media.Acta Acustica(in Chinese),1998,23(2):97~106
[12]张恒山,王庆海.瑞雷面波勘探的波长解释法新探.物探与化探,1998,22(4):279~283Zhang HS,Wang Q H.A newinvestigation into interpretation of wavelength in Rayleigh wave exploration.Geophysical and Geochemical Exploration(in Chinese),1998,22(4):279~283
[13]马在田,曹景忠,王家林等著.计算地球物理学概论.上海:同济大学出版社,1997.20~27Ma Z T,Cao J Z,Wang J L,et al.Conspectus of Computational Geophysics(in Chinese).Shanghai:Tongji University Press,1997.20~27
[14]邵秀民,蓝志凌.非均匀各向同性弹性介质中地震波传播的数值模拟.地球物理学报,1995,38(增刊1):39~55Shao X M,Lan Z L.Numerical simulation of the seismic wave propagation in inhomogeneous isotropic elastic media.Chinese J.Geophys.(in Chinese),1995,38(Suppl.Ⅰ):39~55
[15]孙若昧.地震波传播有限差分模拟的人工边界问题.地球物理学进展,1996,11(3):53~58Sun R M.Artificial boundary problems in finite-difference modeling for seismic wave propagation.Progress in Geophysics(in Chinese),1996,11(3):53~58
[16]楚建伟.瞬态面波技术在冲洪积层勘察中的应用.云南地质,2004,23(1):96~103Chu J W.The application of instant surface wave technique to processing of alluviumand diluvium.Yunnan Geology(in Chinese),2004,23(1):96~103
[17]单娜琳,程志平.高阶模态面波在软弱薄层探测中的应用.桂林工学院学报,2004,24(2):155~158Shan NL,Cheng Z P.Application of high model surface waveinlow velocity thin layer.Journal of Guilin Institute of Technology(in Chinese),2004,24(2):155~158
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心