摘要：2-D seismic modelling has notable dynamic information discrepancies with field data because of the implicit line-source assumption, whereas 3-D modelling suffers from a huge computational burden. The 2.5-D approach is able to overcome both of the aforementioned limitations. In general, the earth model is treated as an elastic material, but the real media is viscous. In this study, we develop an accurate and efficient frequency-domain finite-element method (FEM) formodelling 2.5-D viscoelastic wave propagation. To perform the 2.5-D approach, we assume that the 2-D viscoelastic media are based on the Kelvin-Voigt rheological model and a 3-D point source. The viscoelastic wave equation is temporally and spatially Fourier transformed into the frequency-wavenumber domain. Then, we systematically derive the weak form and its spatial discretization of 2.5-D viscoelastic wave equations in the frequency-wavenumber domain through the Galerkin weighted residual method for FEM. Fixing a frequency, the 2-D problem for each wavenumber is solved by FEM. Subsequently, a composite Simpson formula is adopted to estimate the inverse Fourier integration to obtain the 3-D wavefield. We implement the stiffness reduction method (SRM) to suppress artificial boundary reflections. The results show that this absorbing boundary condition is valid and efficient in the frequency-wavenumber domain. Finally, three numerical models, an unbounded homogeneous medium, a half-space layered medium and an undulating topography medium, are established. Numerical results validate the accuracy and stability of 2.5-D solutions and present the adaptability of finite-element method to complicated geographic conditions. The proposed 2.5-D modelling strategy has the potential to address modelling studies on wave propagation in real earth media in an accurate and efficient way.

关键字：Fourier analysis Numerical solutions Seismic attenuation Seismic tomography Wave propagation

ISSN号：0956-540X

卷、期、页：卷: 211 期: 1 页: 164-187

发表日期：2017-10-01

影响因子：2.414000

期刊分区（SCI为中科院分区）：三区

收录情况：SCI（科学引文索引印刷版）,ESI（基本科学指标数据库）,EI（工程索引）,SCIE（科学引文索引网络版）

发表期刊名称：Geophysical Journal International

参与作者：刘伟方,赵维俊,宋建勇,熊彬

通讯作者：黄兴兴

第一作者：赵建国,王尚旭

论文类型：期刊论文

论文概要：赵建国,黄兴兴,刘伟方,赵维俊,宋建勇,熊彬,王尚旭，2.5-D frequency-domain viscoelastic wave modelling using finite-element method，Geophysical Journal International，2017，卷: 211 期: 1 页: 164-187

论文题目：2.5-D frequency-domain viscoelastic wave modelling using finite-element method