Three-dimensional reflectivity method for complicated irregular formations

• Published in: Soil dynamics and earthquake engineering (1984) Vol. 12; no. 3; pp. 173 - 182
• Main Authors: Jiang, Tong, Nishioka, Shozo, Nagasaka, Hideaki, Kuribayashi, Eiich
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1993; Elsevier Science
• Subjects: Applied geophysics; Earth sciences; Earth, ocean, space; Exact sciences and technology; Internal geophysics; equations; mathematical methods; SH-waves; reflectance; three-dimensional models; topography; two-dimensional models; P-waves; transfer functions; layered materials; boundary conditions; SV-waves
• ISSN: 0267-7261; 1879-341X
• DOI: 10.1016/0267-7261(93)90044-R

The reflectivity method for complicated irregular formations has been extended to three-dimensional irregular (layered) topography. The Aki-Larner technique is generalized to solve the integral equations for 3-D boundary conditions, and propagator matrices are enlarged to express the total wave-field. The formulation in terms of the propagator matrix has been applied to horizontal layers included in the irregularity. The model can simulate more complex, layered, topography. Frequency responses on the surface of 2-D and 3-D layered soft basins are calculated for incident plane waves. They compare favorably with the results of another boundary method. Transfer function versus dimensionless frequency has been also calculated for the 2-D layered soft basin. Significant differences between the layered model and the homogeneous model have been observed; therefore it is necessary to consider the complicated irregular formations at the actual site.