CS/CP IN SANDS AND CLAYS AS A FUNCTION OF MICROSTRUCTURE AND WAVE AMPLITUDE
E.B. Sibiryakov
Institute of Geophysics, Siberian Branch of the RAS, 3 prosp. Akad. Koptyuga, Novosibirsk, 630090, Russia
Keywords: Sands and clays, essential nonlinearity, nonlinear dispersion, microheterogeneity, microstructure, dry friction, mean grain size, mean number of grain contacts
Pages: 258-262
Abstract
Propagation of finite-amplitude waves in friable sands and clays and small-amplitude waves in clays is described by equations of motion using a long-wavelength approximation and differential rather than difference operators. Both linear and nonlinear propagation parameters of P and S waves depend on the microstructure of the medium, and this dependence has been theoretically predicted for the first time for clays of isotropic cellular structure. The energy of seismic waves is much lower than in explosions because of energy transfer into the low-frequency domain. Nonsimultaneous generation of P and S waves in explosions may cause difference in their frequencies. The reported theoretical results agree with the available experimental data.
|
