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Propagation and amplification of seismic waves in 2‐D valleys excited by obliquely incident P‐ and SV‐waves
Author(s) -
Papageorgiou Apostolos S.,
Kim Jaekwan
Publication year - 1993
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.4290220206
Subject(s) - seismic wave , love wave , seismology , geology , mechanical wave , surface wave , wave propagation , diffraction , rayleigh wave , boundary (topology) , p wave , longitudinal wave , physics , geophysics , geometry , optics , medicine , mathematical analysis , mathematics , cardiology , atrial fibrillation
The seismic motion in sediment‐filled valleys due to incident SH‐waves has been studied exhaustively. However, the response of such geologic structures to incident SV‐ and P‐waves has not been studied as thoroughly. The response of a 2‐D model of the valley of Caracas, Venezuela—a NS cross‐section through the Palos Grandes district—to incident plane SV‐ and P‐waves is investigated using the discrete wave number boundary element method. It is observed that the differences in the predictions of the 1‐D and 2‐D models are more pronounced for SV‐waves than for SH‐waves, especially when SV‐waves are incident at (or near) the critical angle i c . The valley responds very strongly to the horizontally propagating P‐wave (SP‐wave) which is induced when SV‐waves, incident at the critical angle, interact with the free surface of the half‐space. However, the SP‐wave, being a wave diffracted at a boundary, is likely to be sensitive to impedance contrasts, to the presence of other interfaces in the medium, and to the topography surrounding the valley. These aspects of the problem need further investigation.