Stable discontinuous grid implementation for collocated-grid finite-difference seismic wave modelling
Stable discontinuous grid implementation for collocated-grid finite-difference seismic wave modelling
复制标题
并置网格有限差分地震波建模的稳定不连续网格实现
DOI：
10.1093/gji/ggs069
复制
发表时间：
2013-03
影响因子：
2.8
通讯作者：
Chen, Xiaofei
中科院分区：
文献类型：
--
作者：
Zhang, Zhenguo;Zhang, Wei;Li, Hong;Chen, Xiaofei
摘要在非均匀高速介质中模拟地震波时，采用均匀网格时，需要根据全局最小速度确定较小的网格间距，导致网格点数多、时间步长小。为了降低计算成本，需要在浅低速区使用较细网格和在高速区使用较粗网格的不连续网格。在本文中，我们提出了一个不连续的网格实现同位网格有限差分（FD）方法，以提高地震波模拟的效率。网格间距比n可以是n ≥ 2的任意整数。为了将波场从更精细的网格下采样到更粗糙的网格，我们的实现可以简单地在更精细的网格上取值，而不采用网格间距比n = 2的下采样滤波器，以实现长期模拟的稳定结果。当网格间距比n ≥ 3时，为了得到稳定的仿真结果，需要采用高斯滤波器作为下采样滤波器。为了将波场从粗网格插值到细网格，使用三线性插值。该方法结合了非连续网格的高效性和曲线网格上同位网格有限差分法的灵活性，能够模拟考虑地表地形影响的真实的大范围高频强地震动。
SUMMARY Simulating seismic waves with uniform grid in heterogeneous high-velocity contrast media requires small-grid spacing determined by the global minimal velocity, which leads to huge number of grid points and small time step. To reduce the computational cost, discontinuous grids that use a finer grid at the shallow low-velocity region and a coarser grid at highvelocity regions are needed. In this paper, we present a discontinuous grid implementation for the collocated-grid finite-difference (FD) methods to increase the efficiency of seismic wave modelling. The grid spacing ratio n could be an arbitrary integer n ≥ 2. To downsample the wavefield from the finer grid to the coarser grid, our implementation can simply take the values on the finer grid without employing a downsampling filter for grid spacing ratio n = 2 to achieve stable results for long-time simulation. For grid spacing ratio n ≥ 3, the Gaussian filter should be used as the downsampling filter to get a stable simulation. To interpolate the wavefield from the coarse grid to the finer grid, the trilinear interpolation is used. Combining the efficiency of discontinuous grid with the flexibility of collocated-grid FD method on curvilinear grids, our method can simulate large-scale high-frequency strong ground motion of real earthquake with consideration of surface topography.
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影响因子：
3.3
作者：
Saenger, EH;Bohlen, T
通讯作者：
Bohlen, T
DOI：
--
发表时间：
2009
期刊：
Chinese Journal of Geophysics
影响因子：
--
作者：
D. Liang
通讯作者：
D. Liang
影响因子：
2.8
作者：
Zhang, Wei;Chen, Xiaofei
通讯作者：
Chen, Xiaofei
影响因子：
3
作者：
Xiaofei Chen
通讯作者：
Xiaofei Chen
影响因子：
3
作者：
K. Hayashi;D. Burns;M. Toksöz
通讯作者：
K. Hayashi;D. Burns;M. Toksöz