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Transient scattering of elastic waves by dipping layers of arbitrary shape. Part 2: Plane strain model
Author(s) -
Eshraghi Hossein,
Dravinski Marijan
Publication year - 1989
Publication title -
earthquake engineering and structural dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.218
H-Index - 127
eISSN - 1096-9845
pISSN - 0098-8847
DOI - 10.1002/eqe.4290180309
Subject(s) - scattering , traction (geology) , displacement (psychology) , physics , fourier transform , geometry , displacement field , transient (computer programming) , boundary value problem , plane (geometry) , optics , mechanics , mathematics , geology , finite element method , psychology , geomorphology , computer science , psychotherapist , thermodynamics , operating system , quantum mechanics
Scattering of elastic waves by dipping layers of arbitrary shape embedded within an elastic half‐space is investigated for a plane strain model by using a boundary method. Unknown scattered waves are expressed in the frequency domain in terms of wave functions which satisfy the equations of motion and appropriate radiation conditions at infinity. The steady state displacement field is evaluated throughout the elastic medium for different incident waves so that the continuity conditions along the interfaces between the layers and the traction‐free conditions along the surface of the half‐space are satisfied in the least‐squares sense. Transient response is constructed from the steady state one through the Fourier synthesis. The results presented show that scattering of waves by dipping layers may cause locally very large amplification of surface ground motion. This amplification depends upon the type and frequency of the incident wave, impedance contrast between the layers, component of displacement which is being observed, location of the observation station and the geometry of the subsurface irregularity. These results are in agreement with recent experimental observations.