Effects of Soil Parameters Uncertainties on the Behaviour of Anisotropic Porous Media to Shear Waves

2019 ◽  
Vol 10 (2) ◽  
pp. 32-49
Author(s):  
Amina Sadouki ◽  
Zamila Harichane ◽  
Ayfer Erken
Keyword(s):  
Porous Media ◽  
Phase Velocity ◽  
Random Media ◽  
Wave Equations ◽  
Shear Waves ◽  
Anisotropic Fluid ◽  
Soil Parameters ◽  
Anisotropic Porous Media ◽  
Practical Applications ◽  
Phase Velocity And Attenuation

In the present study, the wave equations for shear waves propagating in anisotropic fluid-saturated porous media are established in order to obtain the solutions in terms of displacements and dispersion equation. The wave velocities in the vertical and horizontal directions are derived. The uncertainties of the soil parameters due to their spatial variability are taken into account via Monte Carlo Simulations. The results are restricted to the effects of the porosity and permeability uncertainties on the phase velocity and attenuation for SH wave in addition to the anisotropy for Love wave. Results show that the mean velocities are more sensitive to the random variations of the permeability than to that of the porosity, but both phase velocity and attenuation decrease as the uncertainties increase. On the other hand, the anisotropy level and the randomness significantly affect the dispersion of Love waves. The present approach which converts a deterministic solution in a probabilistic one may be used as an everyday tool for practical applications of shear wave propagation in random media.

Circumferential Waves of Infinite Hollow Poroelastic Cylinders

2005 ◽  
Vol 73 (4) ◽  
pp. 705-708 ◽  
Author(s):  
M. Tajuddin ◽  
S. Ahmed Shah
Keyword(s):  
Porous Media ◽  
Wave Propagation ◽  
Phase Velocity ◽  
Elastic Solid ◽  
Frequency Equation ◽  
Saturated Porous Media ◽  
Biot’S Theory ◽  
Phase Velocity And Attenuation ◽  
Special Case ◽  
Circumferential Waves

Employing Biot’s theory of wave propagation in liquid saturated porous media, the frequency equation of circumferential waves for a permeable and an impermeable surface of an infinite hollow poroelastic cylinder is derived in the presence of dissipation and then discussed. Phase velocity and attenuation are determined for different dissipations and then discussed. By ignoring liquid effects, the results of purely elastic solid are obtained as a special case.

Measurements of sound propagation in narrow tubes

2007 ◽  
Vol 463 (2087) ◽  
pp. 2855-2862 ◽  
Author(s):  
T Yazaki ◽  
Y Tashiro ◽  
T Biwa
Keyword(s):  
Porous Media ◽  
Phase Velocity ◽  
Attenuation Coefficient ◽  
Sound Propagation ◽  
Circular Tube ◽  
Anomalous Dispersion ◽  
Starting Point ◽  
Wide Range ◽  
Phase Velocity And Attenuation

The propagation of sound in hollow tubes is a fundamental theme common to many areas of classical acoustics. Kirchhoff's theory explaining the propagation of sound in a circular tube is now playing an important role as a starting point in studying sound in porous media. This paper reports on measurements of the phase velocity and attenuation coefficient in the narrow regions of tubes, where the sound undergoes anomalous dispersion and is seen to slow down remarkably to the extent that a runner can pass ahead of it. Kirchhoff's theory can be verified by experiment over a wide range of thermodynamical conditions, from isentropic to isothermal.

scholarly journals Shear Wave Propagation in Multilayered Medium including an Irregular Fluid Saturated Porous Stratum with Rigid Boundary

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Ravinder Kumar ◽  
Dinesh Kumar Madan ◽  
Jitander Singh Sikka
Keyword(s):  
Phase Velocity ◽  
Half Space ◽  
Perturbation Technique ◽  
Shear Waves ◽  
Elastic Half Space ◽  
Wave Number ◽  
Anisotropic Fluid ◽  
Homogeneous Layer ◽  
Dimensionless Wave Number ◽  
Rigid Boundary

The present investigation is concerned with the study of propagation of shear waves in an anisotropic fluid saturated porous layer over a semi-infinite homogeneous elastic half-space lying under an elastic homogeneous layer with irregularity present at the interface with rigid boundary. The rectangular irregularity has been taken in the half-space. The dispersion equation for shear waves is derived by using the perturbation technique followed by Fourier transformation. Numerically, the effect of irregularity present is analysed. It is seen that the phase velocity is significantly influenced by the wave number and the depth of the irregularity. The variations of dimensionless phase velocity against dimensionless wave number are shown graphically for the different size of rectangular irregularities with the help of MATLAB.

Elastic waves in finely layered sediments: The equivalent medium and generalized O’Doherty‐Anstey formulas

Geophysics ◽  
1996 ◽  
Vol 61 (5) ◽  
pp. 1282-1300 ◽  
Author(s):  
Sergei A. Shapiro ◽  
Peter Hubral
Keyword(s):  
Phase Velocity ◽  
Multiple Scattering ◽  
Random Media ◽  
Plane Waves ◽  
Low Frequency ◽  
Analytic Solutions ◽  
Seismic Velocities ◽  
Statistical Parameters ◽  
Practical Applications ◽  
Backus Averaging

We study the influence of elastic 1-D inhomogeneous random media (e.g., finely layered media with variable density and shear and compressional velocities) on the kinematics and dynamics of the transmitted obliquely incident P‐ and SV‐plane waves. Multiple scattering (resulting in localization and spatial dispersion of the elastic wavefield) is the main physical effect controlling the properties of the wavefield in such media. We analyze the wave propagation assuming the fluctuations of velocities and density to be small (of the order of 20% or smaller). We obtain explicit analytic solutions for the attenuation coefficient and phase velocity of the transmitted waves. These solutions are valid for all frequencies. They agree very well with results of numerical modeling. Our theory shows that fine elastic multilayering is characterized by a frequency‐dependent anisotropy. At typical acquisition frequencies this anisotropy differs significantly from the low‐frequency anisotropy described by the well‐known Backus averaging. The increase of the phase velocity with frequency is quantified. It can partly explain the difference between well‐log‐derived velocities and lower frequency seismic velocities [e.g., vertical seismic profiling (VSP) velocities] in terms of localization. The low‐ and high‐frequency asymptotical results for the phase velocity agree with those of Backus averaging and ray approximation, respectively. The theory describes the angle‐dependent attenuation caused by multiple scattering. The proposed formulas are simple enough to be used in many practical applications as, e.g., in an amplitude variation with offset (AVO) analysis. They can be implemented for taking into account the angle dependence of transmission effects, or they can be used in an inversion for statistical parameters of sediments.

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