Seismic response of a single and a set of filled joints of viscoelastic deformational behaviour

Jianbo Zhu, A. Perino, G. F. Zhao, G. Barla, J. C. Li, G. W. Ma, J. Zhao

Research output: Journal article publicationJournal articleAcademic researchpeer-review

79 Citations (Scopus)

Abstract

Rock joints are often filled with weak medium, for example, saturated clay or sand, of viscoelastic nature. Their effects on wave propagation can be modelled as displacement and stress discontinuity conditions. The viscoelastic behaviour of the filled joint can be described by either the Kelvin or the Maxwell models. The analytical solutions for wave propagation across a single joint are derived in this paper by accounting for the incident angle, the non-dimensional joint stiffness, the non-dimensional joint viscosity and the acoustic impedance ratio of the filled joint. It is shown that the viscoelastic behaviour results in dissipation of wave energy and frequency dependence of the reflection and transmission coefficients. Based on curve fitting of the experimental data of P-wave propagation across a single joint filled with saturated sand, both the Kelvin and Maxwell models are found to reproduce the behaviour of the filled joint, in terms of the amplitude and frequency contents. Then, wave transmission across a filled joint set is studied with the virtual wave source method and the scattering matrix method, where multiple wave reflections among joints are taken into account. It is shown that the non-dimensional joint spacing and the number of joints have significant effects on the transmission coefficients.
Original languageEnglish
Pages (from-to)1315-1330
Number of pages16
JournalGeophysical Journal International
Volume186
Issue number3
DOIs
Publication statusPublished - 1 Sep 2011
Externally publishedYes

Keywords

  • Body waves
  • Rheology and friction of fault zones
  • Seismic anisotropy
  • Seismic attenuation
  • Wave propagation

ASJC Scopus subject areas

  • Geophysics
  • Geochemistry and Petrology

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