Scattering of seismic waves by cracks in multi-layered geological regions: II. Numerical results

✍ Scribed by Petia S Dineva; George D Manolis

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 965 KB
• Volume: 21
• Category: Article
• ISSN: 0267-7261
• DOI: 10.1016/s0267-7261(01)00034-3

✦ Synopsis

The mechanical model for plane strain, time-harmonic seismic wave propagation problems in cracked, multi-layered geological regions with surface topography and non-parallel interfaces was described in the ®rst part of this work. Here, this model is used to investigate the response of such a region to the presence of traveling elastic waves generated by a seismic source. The computational methodology that was developed in the ®rst part is based on a combination of both the regular (displacement-based) and the hypersingular (traction-based) Boundary Integral Equation Method (BIEM). First, the accuracy and convergence characteristics of this hybrid BIEM are studied. Then, a series of problems involving four different con®gurations of a reference geological deposit with both interface and internal cracks are solved, for a loading that is due to a seismically-induced pressure wave propagating upwards from the underlying rigid half-plane. The purpose of the numerical study is to investigate the in¯uence of various key parameters of the problem, such as frequency and incidence angle of the incoming wave, size of the surface relief, location and size of the buried cracks, interaction effects between cracks and ®nally the presence of layers, on both the scattered displacement ®eld and the stress concentration ®eld.