Scattering of rayleigh and longitudinal seismic waves on the local irregularity of the ground
DOI:
https://doi.org/10.7242/1999-6691/2024.17.2.18Keywords:
seismic surface Rayleigh and longitudinal body waves, scattering, single ground unevennessAbstract
A three-dimensional (3D) numerical simulation of scattering of seismic surface Rayleigh and longitudinal waves propagating through the ground, the density and elasticity of which are typical of geomedium. At the soil boundary, there is local unevenness in the form of a hollow hemispherical notch (a truncated sphere). The dependence of the direction of the scattering field on the type of inhomogeneity is shown. From literature it is known that in the transition to another type of heterogeneity, for instance, to covering the boundary with a thin inert (massive) layer in the form of a circle, the forward scattering occurs. A pulsed mode of inhomogeneity probing is considered. As an emitter, it is proposed to use a short pulse source, e.g., a hydroacoustic emitter, or something similar - a pulsating monopole, shallowly immersed under the free boundary. This leads to the generation of such elastic waves as the surface Rayleigh and back-reflected longitudinal waves, which are usually recorded using an array of seismic receivers installed on the free boundary according to the grid pattern. The spatial amplitude distribution of the wave field is analyzed in the vertical (at the center of the inhomogeneity) and horizontal (at the free boundary) sections of the medium. The characteristic features of the wave field are caused by the influence of its scattering on the local inhomogeneity. The features in the image of wave reliefs that arise at the intersection of the wave fronts of longitudinal waves - reflected from the free boundary and scattered on the local inhomogeneity - are studied. Informative signs, indicating the presence of the local heterogeneity and enable diagnostics of its parameters are established. The ways to improve the validity and reliability of algorithms for detection and classification of inhomogeneities and for evaluation of their difficulties using the listed types of waves are discussed. Based on the use of increasingly shorter probing pulses, the possibility of a detailed representation of reliefs and, consequently, the potentially achievable spatial resolution in probing the local subsurface inhomogeneities are demonstrated.
Downloads
References
Zhostkov R.A. Reconstruction of Inhomogeneities of a Medium During Microseismic Sounding Along a Curvilinear Surface. Acoustical Physics. 2019. Vol. 65, no. 5. P. 611–622. DOI: 10.1134/S1063771019050208.
Vlasov S.N., Pavlova G.D., Zhuravlev A.N., Vlasova V.N. Research of defects in manufacturing hot-rolled pipes. Modern Scientific Research: Actual Issues, Achievements and Innovations: XIX International Scientific and Practical Conference, Penza, 5 June 2021. Vol. 1. Penza: Nauka i Prosveshcheniye, 2021. P. 109–111.
Viktorov I.A. Fizicheskiye osnovy primeneniya ul’trazvukovykh voln Releya i Lemba v tekhnike. Moscow, Nauka, 1966. 168 p.
Abbakumov K.A., Konovalov R.S. Scattering Rayleigh wave by the crack with faces in partial contact normal to the surface of the elastic half-space. Izvestiya SPbGETU “LETI”. 2012. No. 1. P. 74–80.
Razin A.V. Scattering of a Rayleigh surface acoustic wave by a small-size inhomogeneity in a solid half-space. Radiophysics and Quantum Electronics. 2010. Vol. 53. P. 417–431. DOI: 10.1007/s11141-010-9239-3.
Samedov Y.Y., Kutianin V.V. Rayleigh wave leakage on surface defects. NDT WORLD. 2008. No. 1. P. 34–35.
Zaslavskii Y.M. Parametric scattering of high-frequency elastic waves by a small spherical cavity oscillating under the action of a Rayleigh wave. Acoustical Physics. 2004. Vol. 50. P. 46–51. DOI: 10.1134/1.1640724.
Ermolov I.N. Progress in the theory of ultrasonic flaw detection. Problems and prospects. Russian Journal of Nondestructive Testing. 2004. Vol. 40. P. 655–678. DOI: 10.1007/s11181-004-0015-3.
Chukov V.N. Rayleigh wave scattering by statistical inhomogeneity of mass density. Physics of the Solid State. 1997. Vol. 39, no. 2. P. 233–239. DOI: 10.1134/1.1129791.
Kosachev V.V., Lokhov Y.N., Chukov V.N. Rasseyaniye poverkhnostnykh releyevskikh i ob’yemnykh akusticheskikh voln na dvumernoy statisticheskoy sherokhovatosti svobodnoy poverkhnosti tverdogo tela. Physics of the Solid State. 1990. Vol. 32, no. 7. P. 2045–2055.
Zaslavskiy Y.M. Energetika rasseyannykh uprugikh poley, voznikayushchikh pri difraktsii volny Releya na poverkhnostnom vozmushchenii poluogranichennoy sredy. 1989. 15 p.
Angel Y.C., Achenbach J.D. Reflection and transmission of obliquely incident Rayleigh waves by a surface-breaking crack. The Journal of the Acoustical Society of America. 1984. Vol. 75, no. 2. P. 313–319. DOI: 10.1121/1.390473.
Hirao M., Fukuoka H., Miura Y. Scattering of Rayleigh surface waves by edge cracks: Numerical simulation and experiment. The Journal of the Acoustical Society of America. 1982. Vol. 72, no. 2. P. 602–606. DOI: 10.1121/1.388041.
Krylov V.V. Optical theorem for the scattering of strain waves by inhomogeneities of the plane boundary of a solid. Soviet Physics Acoustics. 1980. Vol. 26. P. 117–119.
Parekh J.P., Tuan H.-S. Reflection and bulk-wave conversion of Rayleigh wave at a single shallow groove. Journal of Applied Physics. 1977. Vol. 48, no. 3. P. 994–1003. DOI: 10.1063/1.323721.
Maradudin A., Mills D. The attenuation of Rayleigh surface waves by surface roughness. Annals of Physics. 1976. Vol. 100, no. 1/2. P. 262–309. DOI: 10.1016/0003-4916(76)90063-4.
Tuan H.-S. On bulk waves excited at a groove by Rayleigh waves. Journal of Applied Physics. 1975. Vol. 46, no. 1. P. 36–41. DOI: 10.1063/1.321345.
Downloads
Published
Issue
Section
License
Copyright (c) 1970 Computational Continuum Mechanics
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.