scholarly journals Surface waves in higher order visco-elastic media under the influence of gravity

1991 ◽  
Vol 4 (1) ◽  
pp. 71-82 ◽  
Author(s):  
Animesh Mukherjee ◽  
P. R. Sengupta ◽  
Lokenath Debnath
Keyword(s):  
Surface Waves ◽  
Wave Velocity ◽  
Rayleigh Waves ◽  
Higher Order ◽  
Love Waves ◽  
Initial Stresses ◽  
Elastic Media ◽  
Perfect Agreement ◽  
Gravitational Effects ◽  
Gravity Effects

Based upon Biot's [1965] theory of initial stresses of hydrostatic nature produced by the effect of gravity, a study is made of surface waves in higher order visco-elastic media under the influence of gravity. The equation for the wave velocity of Stonely waves in the presence of viscous and gravitational effects is obtained. This is followed by particular cases of surface waves including Rayleigh waves and Love waves in the presence of viscous and gravity effects. In all cases the wave-velocity equations are found to be in perfect agreement with the corresponding classical results when the effects of gravity and viscosity are neglected.

Surface waves in homogenous visco-elastic media of higher order under the influence of surface stresses

2013 ◽  
Vol 22 (5-6) ◽  
pp. 185-191 ◽  
Author(s):  
Munish Sethi ◽  
K.C. Gupta ◽  
Monika Rani ◽  
A. Vasudeva
Keyword(s):  
Surface Waves ◽  
Solid Medium ◽  
Elastic Solid ◽  
Higher Order ◽  
Love Waves ◽  
Elastic Media ◽  
Time Rate ◽  
Surface Stresses ◽  
Rayleigh And Love Waves

AbstractThe aim of the present paper is to investigate the surface waves in a homogeneous, isotropic, visco-elastic solid medium of nth order, including time rate of strain under the influence of surface stresses. The theory of generalized surface waves is developed to investigate particular cases of waves such as the Stoneley, Rayleigh, and Love waves. Corresponding equations have been obtained for different cases. These are reduced to classical results, when the effects of surface stresses and viscosity are ignored.

scholarly journals Effect of gravity on visco-elastic surface waves in solids involving time rate of strain and stress of higher order

1995 ◽  
Vol 18 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Tapan Kumar Das ◽  
P. R. Sengupta ◽  
Lokenath Debnath
Keyword(s):  
Surface Waves ◽  
Wave Velocity ◽  
Rayleigh Waves ◽  
General Equation ◽  
Elastic Solid ◽  
Higher Order ◽  
Rate Of Change ◽  
Elastic Surface ◽  
Time Rate ◽  
Stoneley Waves

A study is made of the surface waves in a higher order visco-elastic solid involving time rate of change of strain and stress under the influence of gravity. A fairly general equation for the wave velocity is derived. This equation is used to examine various kinds of surface waves including Rayleigh waves, Love waves and Stoneley waves. It is shown that the corresponding classical results follow from this analysis in the absence of gravity and viscosity.

scholarly journals Surface waves in multilayered elastic media I. Rayleigh and Love waves from buried sources in a multilayered elastic half-space

1964 ◽  
Vol 54 (2) ◽  
pp. 627-679
Author(s):  
David G. Harkrider
Keyword(s):  
Surface Waves ◽  
Frequency Domain ◽  
Half Space ◽  
Rayleigh Waves ◽  
Elastic Half Space ◽  
Love Waves ◽  
Displacement Fields ◽  
Matrix Formulation ◽  
Total Displacement ◽  
Rayleigh And Love Waves

ABSTRACT A matrix formulation is used to derive integral expressions for the time transformed displacement fields produced by simple sources at any depth in a multilayered elastic isotropic solid half-space. The integrals are evaluated for their residue contribution to obtain surface wave displacements in the frequency domain. The solutions are then generalized to include the effect of a surface liquid layer. The theory includes the effect of layering and source depth for the following: (1) Rayleigh waves from an explosive source, (2) Rayleigh waves from a vertical point force, (3) Rayleigh and Love waves from a vertical strike slip fault model. The latter source also includes the effect of fault dimensions and rupture velocity. From these results we are able to show certain reciprocity relations for surface waves which had been previously proved for the total displacement field. The theory presented here lays the ground work for later papers in which theoretical seismograms are compared with observations in both the time and frequency domain.

scholarly journals Characteristics of the horizontal component of Rayleigh waves in multimode analysis of surface waves

Geophysics ◽  
2015 ◽  
Vol 80 (1) ◽  
pp. EN1-EN11 ◽  
Author(s):  
Tatsunori Ikeda ◽  
Toshifumi Matsuoka ◽  
Takeshi Tsuji ◽  
Toru Nakayama
Keyword(s):  
Surface Waves ◽  
Wave Velocity ◽  
Rayleigh Waves ◽  
Field Data ◽  
Vertical Component ◽  
Dispersion Curves ◽  
Horizontal Component ◽  
S Wave ◽  
Higher Modes ◽  
Explosive Source

In surface-wave analysis, S-wave velocity estimations can be improved by the use of higher modes of the surface waves. The vertical component of P-SV waves is commonly used to estimate multimode Rayleigh waves, although Rayleigh waves are also included in horizontal components of P-SV waves. To demonstrate the advantages of using the horizontal components of multimode Rayleigh waves, we investigated the characteristics of the horizontal and vertical components of Rayleigh waves. We conducted numerical modeling and field data analyses rather than a theoretical study for both components of Rayleigh waves. As a result of a simulation study, we found that the estimated higher modes have larger relative amplitudes in the vertical and horizontal components as the source depth increases. In particular, higher-order modes were observed in the horizontal component data for an explosive source located at a greater depth. Similar phenomena were observed in the field data acquired by using a dynamite source at 15-m depth. Sensitivity analyses of dispersion curves to S-wave velocity changes revealed that dispersion curves additionally estimated from the horizontal components can potentially improve S-wave velocity estimations. These results revealed that when the explosive source was buried at a greater depth, the horizontal components can complement Rayleigh waves estimated from the vertical components. Therefore, the combined use of the horizontal component data with the vertical component data would contribute to improving S-wave velocity estimations, especially in the case of buried explosive source signal.

Anomalous surface waves from underground explosions

1979 ◽  
Vol 69 (6) ◽  
pp. 1995-2002 ◽  
Author(s):  
Eivind Rygg
Keyword(s):  
Rayleigh Wave ◽  
Surface Waves ◽  
Rayleigh Waves ◽  
Major Part ◽  
Wave Generation ◽  
Love Waves ◽  
Phase Reversal ◽  
Wave Phase ◽  
Anomalous Surface

abstract The Rayleigh waves at Δ ∼40° from an eastern Kazakh explosion are shown to be polarity reversed and delayed relative to the Rayleigh waves from two other explosions of comparable magnitudes in the same area. The event generating the anomalous Rayleigh waves excited very strong Love waves which were not delayed. The Rayleigh wave phase reversal is shown to be a source phenomenon and it is suggested that in this particular case, spall closure was responsible for a major part of the Rayleigh-wave generation.

scholarly journals Surface waves in non-homogeneous, general magnetothermo, viscoelastic media of higher order

2013 ◽  
Vol 18 (4) ◽  
pp. 1221-1236
Author(s):  
M. Sethi ◽  
K.C. Gupta ◽  
M. Rani
Keyword(s):  
Surface Waves ◽  
Wave Velocity ◽  
Classical Result ◽  
Solid Medium ◽  
Elastic Solid ◽  
Higher Order ◽  
Time Rate ◽  
Viscoelastic Media ◽  
Material Medium

Abstract The aim of the present paper is to investigate surface waves in a non-homogeneous, isotropic, visco-elastic solid medium of n-th order including the time rate of strain. The theory of generalised surface waves has firstly been developed and then it has been employed to investigate particular cases of waves, viz., Stoneley, Rayleigh and Love type. The wave velocity equations have been obtained for different cases and are in well agreement with the corresponding classical result, when the effects of viscosity, temperature, magnetism as well as nonhomogeneity of the material medium are ignored.

Surface waves in fibre-reinforced anisotropic solid elastic media under the influence of gravity

2012 ◽  
Vol 20 (4-6) ◽  
pp. 81-85
Author(s):  
Munish Sethi ◽  
Manisha Gupta ◽  
Kishan Chand Gupta ◽  
Mahinder Singh Saroa ◽  
Deepak Gupta
Keyword(s):  
Surface Waves ◽  
Present Article ◽  
Wave Velocity ◽  
Classical Result ◽  
Solid Medium ◽  
Elastic Solid ◽  
Elastic Media ◽  
Material Medium ◽  
Anisotropic Solid ◽  
Anisotropic Elastic

AbstractThe aim of the present article is to investigate the surface waves in anisotropic, elastic solid medium under the influence of gravity. The theory of generalised surface waves has first been developed and then used to investigate particular cases of waves, viz., Stoneley, Rayleigh, and Love. The wave velocity equations have been obtained for different cases and are in well agreement with the corresponding classical result, when the effect of gravity, viscosity, and fibre-reinforced parameters of the material medium are ignored.

Wave-equation dispersion inversion of Love waves

Geophysics ◽  
2019 ◽  
Vol 84 (5) ◽  
pp. R693-R705 ◽  
Author(s):  
Jing Li ◽  
Sherif Hanafy ◽  
Zhaolun Liu ◽  
Gerard T. Schuster
Keyword(s):  
Wave Equation ◽  
Wave Velocity ◽  
Rayleigh Waves ◽  
Love Wave ◽  
Field Data ◽  
Wave Dispersion ◽  
Dispersion Curves ◽  
Love Waves ◽  
S Wave ◽  
Love Wave Dispersion

We present a theory for wave-equation inversion of Love-wave dispersion curves, in which the misfit function is the sum of the squared differences between the wavenumbers along the predicted and observed dispersion curves. Similar to inversion of Rayleigh-wave dispersion curves, the complicated Love-wave arrivals in traces are skeletonized as simpler data, namely, the picked dispersion curves in the [Formula: see text] domain. Numerical solutions to the SH-wave equation and an iterative optimization method are then used to invert these dispersion curves for the S-wave velocity model. This procedure, denoted as wave-equation dispersion inversion of Love waves (LWD), does not require the assumption of a layered model or smooth velocity variations, and it is less prone to the cycle-skipping problems of full-waveform inversion. We demonstrate with synthetic and field data examples that LWD can accurately reconstruct the S-wave velocity distribution in a laterally heterogeneous medium. Compared with Rayleigh waves, inversion of the Love-wave dispersion curves empirically exhibits better convergence properties because they are completely insensitive to the P-velocity variations. In addition, Love-wave dispersion curves for our examples are simpler than those for Rayleigh waves, and they are easier to pick in our field data with a low signal-to-noise ratio.

scholarly journals Surface Waves in Fibre-Reinforced Anisotropic Solid Elastic Media under the Influence of Gravity

2013 ◽  
Vol 18 (1) ◽  
pp. 177-188 ◽  
Author(s):  
M. Sethi ◽  
K.C. Gupta ◽  
D. Gupta And Manisha
Keyword(s):  
Surface Waves ◽  
Wave Velocity ◽  
Classical Result ◽  
Solid Medium ◽  
Elastic Solid ◽  
Fibre Reinforcement ◽  
Elastic Media ◽  
Material Medium ◽  
Anisotropic Solid ◽  
Anisotropic Elastic

The aim of the present paper is to investigate surface waves in an anisotropic, elastic solid medium under the influence of gravity. First, a theory of generalised surface waves was developed and then it was employed to investigate particular cases of waves, viz., Stoneley and Rayleigh, Love type. The wave velocity equations were obtained for different cases and they are in well agreement with the corresponding classical result, when the effect of gravity, viscosity as well as parameters for fibre-reinforcement of the material medium are ignored.

scholarly journals Multi-channel analysis of surface wave method for geotechnical site characterization in Yogyakarta, Indonesia

2019 ◽  
Vol 76 ◽  
pp. 03006
Author(s):  
Nwai Le Ngal ◽  
Subagyo Pramumijoyo ◽  
Iman Satyarno ◽  
Kirbani Sri Brotopuspito ◽  
Junji Kiyono ◽  
...  
Keyword(s):  
Surface Waves ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Rayleigh Waves ◽  
Influential Factors ◽  
Multichannel Analysis ◽  
Average Shear ◽  
Channel Analysis ◽  
Masw Method

On May 27th 2006, Yogyakarta earthquake happened with 6.3 Mw. It was causing widespread destruction and loss of life and property. The average shear wave velocity to 30 m (Vs30) is useful parameter for classifying sites to predict their potential to amplify seismic shaking (Boore, 2004) [1]. Shear wave velocity is one of the most influential factors of the ground motion. The average shear wave velocity for the top 30 m of soil is referred to as Vs30. In this study, the Vs30 values were calculated by using multichannel analysis of surface waves (MASW) method. The Multichannel Analysis of Surface Waves (MASW) method was introduced by Park et al. (1999). Multi-channel Analysis of Surface Waves (MASW) is non-invasive method of estimating the shear-wave velocity profile. It utilizes the dispersive properties of Rayleigh waves for imaging the subsurface layers. MASW surveys can be divided into active and passive surveys. In active MASW method, surface waves can be easily generated by an impulsive source like a hammer, sledge hammer, weight drops, accelerated weight drops and explosive. Seismic measurements were carried out 44 locations in Yogyakarta province, in Indonesia. The dispersion data of the recorded Rayleigh waves were processed by using Seisimager software to obtain shear wave velocity profiles of the studied area. The average shear wave velocities of the soil obtained are ranging from 200 ms-1 to 988 ms-1, respectively.

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