Finite-difference modeling of faults and fractures
Finite-difference modeling of faults and fractures
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DOI：
10.1190/1.1443884
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发表时间：
1995-10
期刊：
影响因子：
3.3
通讯作者：
R. Coates;M. Schoenberg
中科院分区：
文献类型：
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作者：
R. Coates;M. Schoenberg
出于地震传播的目的，滑断层可被视为地震波引起的位移不连续而应力牵引保持连续的表面。最简单的假设是这种滑移和应力牵引是线性相关的。当断层平行于有限差分网格时，这种线性滑移界面条件很容易建模，但对于任意非平面断层表面则更难建模。为了处理这种情况，我们引入等效介质理论来模拟与断层相交的有限差分网格单元中的材料行为。通过（1）显式滑移界面条件（断层平行于网格）和（2）当有限差分网格相对于断层和接收器阵列旋转时使用等效介质理论对断层进行建模，获得了几乎相同的结果。除了查找相关单元及其关联模数所需的预处理之外，不需要额外的计算时间。该公式足够通用，可以包含任意各向异性材料内部和之间的断层，这些材料的滑移特性随位置而变化。
For the purposes of seismic propagation, a slip fault may be regarded as a surface across which the displacement caused by a seismic wave is discontinuous while the stress traction remains continuous. The simplest assumption is that this slip and the stress traction are linearly related. Such a linear slip interface condition is easily modeled when the fault is parallel to the finite-difference grid, but is more difficult to do for arbitrary nonplanar fault surfaces. To handle such situations we introduce equivalent medium theory to model material behavior in the cells of the finite-difference grid intersected by the fault. Virtually identical results were obtained from modeling the fault by (1) an explicit slip interface condition (fault parallel to the grid) and (2) using the equivalent medium theory when the finite-difference grid was rotated relative to the fault and receiver array. No additional computation time is needed except for the preprocessing required to find the relevant cells and their associated moduli. The formulation is sufficiently general to include faults in and between arbitrary anisotropic materials with slip properties that vary as a function of position.