Hybrid seismic modeling based on discrete-wave number and finite-difference methods
Hybrid seismic modeling based on discrete-wave number and finite-difference methods
复制标题
基于离散波数和有限差分方法的混合地震建模
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
P. Moczo
中科院分区：
文献类型：
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作者：
J. Zahradník;P. Moczo
在单个有限差分（FD）模型中包括震源、行进路径和接收器位置的地震波传播的任何计算都需要相当大量的计算机时间和存储器。此外，目前可用于在2D FD计算中包括点源的方法仅是远场近似。因此，我们发展了一种新的混合方法来处理嵌入在一维背景介质中的局部二维近地表结构上的地震波场，并由点源激发。背景模型中的源辐射和传播采用离散波数（DW）方法求解，而局部二维结构中的传播采用FD方法计算。两组计算之间的耦合在围绕局部结构的矩形激励盒上进行。我们表明，该方法在地面运动的研究，近场源的影响和当地的网站效应是很重要的。与3D源辐射和2D FD计算之间的不一致有关的技术问题对于相对远的面内点爆炸源是次要的，但是对于面内位错源是更严重的。
Any calculation of seismic wave propagation comprising the seismic source, the travel path, and the receiver site in a single finite-difference (FD) model requires a considerable amount of computer time and memory. Moreover, the methods currently available for including point sources in the 2D FD calculations are far-field approximations only. Therefore we have developed a new hybrid method for treating the seismic wave fields at localized 2D near-surface structures embedded in a 1D background medium, and excited by a point source. The source radiation and propagation in the background model is solved by the discrete-wave number (DW) method, while the propagation in the local 2D structure is calculated by the FD method. The coupling between the two sets of calculations is performed on a rectangular excitation box surrounding the local structure. We show the usefulness of the method in ground-motion studies where both near-field source effects and local site effects are important. Technical problems connected with the inconsistency between the 3D source radiation and the 2D FD calculation are minor for the relatively distant in-plane point explosive sources, but are more serious for the in-plane dislocation sources.