Study On Guide Wave Propagation In Saturated Porous Media

Fluid-saturated porous media fluctuation theory, the more traditional single-phase medium theory is closer to engineering practice. Therefore, it seismology, earthquake engineering, soil dynamics, geophysical exploration, acoustic and power base, has a wide-ranging and important applications. In this paper, for the fluid saturated porous media in guided wave has undertaken the following several aspects:Firstly, reviewed the theory of two-phase media research. Then introduced the classification of waves and wave propagation characteristics in the phase velocity, group velocity, wave velocity and wave number, wave dispersion spectrum diagrams and maps, wave attenuation and energy density of the underlying concepts.Secondly, wave equation in the establishment of two-phase media at the same time, re-calculation of the "high-frequency within the framework of fluid-saturated porous media, wave propagation," the original examples in the literature. Found a new calculation results in the calculation results with the literature there are large deviations analysis of some of the reasons for deviation.Thirdly, Overlay of the two-phase media in Love wave theoretical analysis and calculation, analysis of porosity in different situations Love wave dispersion and attenuation characteristics. The results show that there is dispersion of love waves in positive and negative dispersion phenomenon, but also in the low-frequency (seismic wave) within the scope of the Love wave dispersion and attenuation of the changes in porosity are not sensitive to, and in the high-frequency range of the two pairs of porosity more sensitive to changes. Finally study covering layer of Love wave vibration intensity, stress amplitude, can stay in the density as the porosity, as well as the changes of the depth of cover. These conclusions provide a theoretical basis for practical application.Fourthly,the cylindrical fluid interface with the two-phase media have done a theoretical analysis of Stoneley wave and calculation, first of all given Stoneley waves generated by boundary conditions, and then use the given boundary conditions are derived outside the two-phase medium, horizontal cylindrical wave solution and P-wave and the Stoneley wave solution of the complex wave number dispersion equation. In the low-frequency domain of this numerical dispersion equation is solved with the change in porosity of the dispersion curves and attenuation curves and polarization curves. The results showed that: Stoneley-wave attenuation characteristics is not only strong, but low-frequency Stoneley waves exist within a small negative dispersion; in different frequency regions Stonley wave dispersion and attenuation curves affected differently by the porosity; Stoneley wave attenuation coefficient and frequency, porosity exists between an increasing function of the sensitive relationship. Also studied the cylindrical fluid region and two-phase medium with the acoustic pressure within the region to increase the distance from the cylinder center was studied.