Publication Date:
2013-08-13
Description:
A hybrid method to model the shear (SH) wave scattering from 2-D fractures embedded in a heterogeneous medium is developed by coupling the boundary element method (BEM) and the finite different method (FDM) in the frequency domain. FDM is used to propagate an SH wave from a source through heterogeneities to fractures embedded in small local homogeneous domains surrounded by artificial boundaries. According to Huygens’ Principle, the points at these artificial boundaries can be regarded as ‘secondary’ sources and their amplitudes are calculated by FDM. Given the incident fields from these point sources, BEM is applied to model the scattering from fractures and propagate them back to the artificial boundaries. FDM then continues propagating the scattered field into the heterogeneous medium by taking the scattered field at the boundaries as ‘secondary’ sources. A numerical iterative scheme is also developed to account for the multiple scattering between different sets of fractures. The hybrid method can calculate scattering from different fractures very fast, thus Monte Carlo simulations for characterizing the statistics of fracture attributes can be performed efficiently. To verify the hybrid method, we compared scattering from multiple fractures embedded in a homogeneous space by our method and a pure BEM; also, we compared our method with the time-domain finite-difference method for vertical fractures in a layered medium. Good agreements are found. The hybrid method is also applied to calculate the wave scattered from fractures embedded in complex media.
Print ISSN:
0956-540X
Electronic ISSN:
1365-246X
Topics:
Geosciences
Published by
Oxford University Press
on behalf of
The Deutsche Geophysikalische Gesellschaft (DGG) and the Royal Astronomical Society (RAS).
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