A fast implementation of boundary integral equation methods to calculate the propagation of seismic waves in laterally varying layered media
A fast implementation of boundary integral equation methods to calculate the propagation of seismic waves in laterally varying layered media
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发表时间：
1995-12
影响因子：
3
通讯作者：
M. Bouchon;C. Schultz;M. Toksöz
中科院分区：
文献类型：
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作者：
M. Bouchon;C. Schultz;M. Toksöz
摘要本文提出了一种边界积分方程/共轭梯度法来研究地震波在复杂地质结构中的传播。该方法的目的是将边界积分方程或边界元法的应用范围扩展到相对较大规模或复杂的地质模型。我们表明，系统的方程，表示在介质界面的边界条件，这是固有的biem或bem的方法可以大大减少的大小，只有10至20%的条款，这个系统的解决方案作出了重大贡献。因此，边界条件可以以非常稀疏的线性系统的形式表示，该线性系统可以通过共轭梯度法迭代地反演。我们使用这种方法来研究不同厚度的沉积层对局部和区域地震波传播的影响。我们表明，当沉积物/基岩界面相对于平坦的情况粗糙且不规则时，地面运动的振幅和振动持续时间会急剧增加。
Abstract We present a boundary integral equation/conjugate gradient formulation to study the propagation of seismic waves through complex geological structures. The method is aimed at extending the range of applications of boundary integral equations or boundary element methods to geological models of relatively large size or complexity. We show that the system of equations that expresses the boundary conditions at the medium interfaces and that is inherent to the biem or bem approach can be drastically reduced in size and that only 10 to 20% of the terms of this system contribute significantly to the solution. The boundary conditions may thus be expressed in the form of a very sparse linear system that can be inverted iteratively by the conjugate gradient method. We use this approach to investigate the effect of a sedimentary layer of varying thickness on local and regional seismic wave propagation. We show that the amplitude of ground motion and the duration of shaking are drastically increased when the sediment/bedrock interface is rough and irregular relatively to the case where it is flat.