INFLUENCE OF VISCOUS COUPLING IN PROPAGATION OF ELASTIC WAVES IN SATURATED SOIL

The interactions between the solid and fluid phases of saturated porous media are due to inertial, viscous, and mechanical coupling. More specifically, viscous coupling is crucial because it makes wave propagation dispersive. The author provides a detailed analysis on the effects of viscous coupling on the mechanics of transient wave propagation by considering the propagation of simple shaped driving pulses for both constant and frequency-dependent viscous coupling. Specific attention is given to the interpretation of dynamic soil test measurements, because of their importance in the current practice of soil investigation, both in laboratory and in situ. Results reveal that it is possible to identify two extreme kinds of transient behavior: in the first, the porous medium serves as a two-phase medium in which the velocity of propagation corresponds to null viscous coupling; in the second, the behavior corresponds to a one-phase medium with velocity of propagation corresponding to infinite viscous coupling. A gradual transition occurs between these two extreme behaviors, but it extends for quite a narrow range of values of travel length and of the coefficient of permeability for a given frequency content of the driving pulse. These conclusions are useful for interpreting dynamic measurements and should enhance the comprehension of the mechanics of dispersive wave propagation in saturated porous media.

Language

  • English

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: p. 636-644
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00711516
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Sep 8 1995 12:00AM