DOI QR코드

DOI QR Code

Stochastic numerical study on the propagation characteristics of P-Wave in heterogeneous ground

지반의 비균질성이 탄성파 전파 특성에 미치는 영향에 대한 추계론적 수치해석 연구

  • Song, Ki-Il (Department of Civil Engineering, Inha University)
  • Received : 2012.11.19
  • Accepted : 2013.01.07
  • Published : 2013.01.31

Abstract

Various elastic wave-based site investigation methods have been used to characterize subsurface ground because the dynamic properties can be correlated with various geotechnical parameters. Although the inherent spatial variability of the geotechnical parameters affects the P-wave propagation characteristics, ground heterogeneity has not been considered as an influential factor. Thus, the effect of heterogeneous ground on the travel-time shift and wavefront characteristics of elastic waves through stochastic numerical analyses is investigated in this study. The effects of the relative correlation lengths and relative propagation distances on the travel-time shift of P-waves considering various intensities of ground heterogeneity were investigated. Heterogeneous ground fields of stiffness (e.g., the coefficient of variation = 10 ~ 40%) were repeatedly realized in numerical finite difference grids using the turning band method. Monte Carlo simulations were undertaken to simulate P-wave propagation in heterogeneous ground using a finite difference method-based numerical approach. The results show that the disturbance of the wavefront becomes more significant with stronger heterogeneity and induces travel-time delays. The relative correlation lengths and propagation distances are systematically related to the travel-time shift.

현재 다양한 탄성파 기반의 물리탐사 기법들이 지반조사를 위해 널리 이용되고 있는데 이는 지반의 동적 특성들이 공학적 물성과 상관관계를 갖기 때문이다. 하지만, 지반공학적 물성치들의 고유한 비균질성이 탄성파 속도 및 진폭 등의 전파 특성에 영향을 미침에도 불구하고 그에 대한 고려가 안되고 있는 실정이다. 그래서, 본 연구에서는 지반의 고유한 비균질성이 탄성파 전파특성에 미치는 영향을 규명하기 위하여 추계론적 수치해석 방법을 적용하였다. 탄성파의 도달 시간 변화와 파두 특성에 주안점을 두어 분석을 수행하였다. 지반의 공간적 상관 거리와 파장과의 상관성 및 탄성파 전파거리와 파장과의 상관성이 탄성파의 도달 시간 변화에 미치는 영향에 대하여 조사하였다. Turning band method를 적용하여 변동계수의 범위가 10 ~ 40%인 다양한 비균질 강도를 갖는 지반을 유한차분 그리드에 생성하였다. 유한차분법을 이용하여 비균질 지반에서 탄성파의 전파를 시뮬레이션하였고, 추계론적 기법으로는 Monte Carlo 시뮬레이션 기법을 적용하였다. 추계론적 수치해석 결과, 지반의 비균질 강도가 증가함에 따라 탄성파의 파두 형상의 일그러짐이 현저하게 발생하였고, 그에 따라 탄성파의 도달 시간도 지연되는 것으로 나타났다. 지반의 공간적 상관 거리와 파장과의 상관성 및 탄성파 전파 거리와 파장과의 상관성은 탄성파의 도달 시간 변화와 긴밀한 상관성이 있는 것으로 나타났다.

Keywords

References

  1. Song, K.I., Cho, G.C. (2006), "Effect of spatial distribution of geotechnical parameters on tunnel deformation", Journal of Korean Tunnelling and Underground Space Association, Vol. 8, No. 3, pp. 249-257.
  2. Song, K.I., Cho, G.C., Lee, S.W. (2011), "Effects of spatially variable weathered rock properties on tunnel behavior", Probabilistic Engineering Mechanics, Vol. 26, No. 3, pp. 413-426. https://doi.org/10.1016/j.probengmech.2010.11.010
  3. Baig, A.M., Dahlen, F.A., Hung, S.H. (2003), "Traveltimes of waves in three-dimensional random media", Geophys. J. Int., Vol. 153, pp. 467-482. https://doi.org/10.1046/j.1365-246X.2003.01905.x
  4. Dahlen, F.A., Hung, S.H, Nolet, G. (2000), "Frẻchet kernels for finite frequency traveltimes-I. Theory", Geophys. J. Int., Vol. 141, pp. 157-174. https://doi.org/10.1046/j.1365-246X.2000.00070.x
  5. Fehler, M., Sato, H., Huang, L.J. (2000), "Envelope broadening of outgoing waves in 2D random media: a comparison between the Markov approximation and numerical simulations", Bull. Seismol. Soc. Am., Vol. 90, No. 4, pp. 914-928. https://doi.org/10.1785/0119990143
  6. Hador, R.B., Buchen, P.W. (1999), "Love and rayleigh waves in non-uniform media", Geophys. J. Int., Vol. 137, pp. 521-534.
  7. Horike, M., Takeuchi, Y. (2000), "Possibility of spatial variation of high-frequency seismic motions due to random-velocity fluctuation of sediments", Bull. Seismol. Soc. Am., Vol. 90, No. 1, pp. 48-65. https://doi.org/10.1785/0119980040
  8. Hung, S.H., Dahlen, F.A., Nolet, G. (2000), "Frechet kernels for finite frequency traveltimes-II. examples", Geophys. J. Int., Vol. 141, pp. 175-203. https://doi.org/10.1046/j.1365-246X.2000.00072.x
  9. Iooss, B. (1998), "Seismic reflection traveltimes in two-dimensional statistically anisotropic random media", Geophys. J. Int., Vol. 135, No. 3, pp. 999-1010. https://doi.org/10.1046/j.1365-246X.1998.00690.x
  10. Itasca Consulting Group Inc. (2002), FLAC - Fast Lagrangian Analysis of Continua User's Guide, Itasca Consulting Group, Inc., Minneapolis, MN.
  11. Jones, A.L., Kramer, S.L., Arduino, P. (2002), "Estimation of uncertainty in geotechnical properties for performance-based earthquake engineering", PEER report 2002/16. p. 114.
  12. Kim, J., Song, K.I., Cho, G.C., Lee, S.W. (2008), "Evaluation of the time-dependent characteristics of grouted particulate", Modern Physics Letters B, Vol. 22, No. 11, pp. 899-904. https://doi.org/10.1142/S0217984908015577
  13. Lantuejoul, C. (1994), "Non conditional simulation of stationary isotropic multigaussian random functions", In: Armstrong, M., Dowd, P.A. (Eds.), Geostatistical Simulations, Kluwer Academic, Dordrecht, pp. 147-177.
  14. Lee, I.M., Choi, S.S., Kim, S.T., Kim, C.K., Jun. J.S. (2002), "3D analysis of fracture zones ahead of tunnel face using seismic reflection", Journal of Korean Tunnelling and Underground Space Association, Vol. 4, No. 4, pp. 301-317.
  15. Li, X., Hudson, J.A. (1996), "Multiple scattering of elastic waves from a continuous and heterogeneous region", Geophys. J. Int., Vol. 126, pp. 845-862. https://doi.org/10.1111/j.1365-246X.1996.tb04707.x
  16. Lysmer, J., Kuhlemeyer, R.L. (1969), "Finite Dynamic Model for Infinite Media", Journal of the Engineering Mechanics Division, ASCE, Vol. 95, pp. 859-877.
  17. Marion, D., Mukerji, T., Mavko, G. (1994), "Scale effects on velocity dispersion: from ray to effective medium theories in stratified media", Geophysics, Vol. 59, pp. 1613-1619. https://doi.org/10.1190/1.1443550
  18. Matheron, G. (1973), "The intrinsic random functions and their applications", Advances in Applied Probability, Vol. 5, pp. 439-468. https://doi.org/10.2307/1425829
  19. Mavko, G., Mukerji, T., Dvorkin, J. (1998), The rock physics handbook, Cambridge University Press. p. 511.
  20. Metropolis, N., Ulam, S. (1949), "The monte carlo method", Journal of the American Statistical Association, Vol. 44, No. 247, pp. 335-341. https://doi.org/10.1080/01621459.1949.10483310
  21. Mukerji, T., Mavko, G., Mujica, D., Lucet, N. (1995), "Scale-dependent seismic velocity in heterogeneous media", Geophysics, Vol. 60, No. 4, pp. 1222-1233. https://doi.org/10.1190/1.1443851
  22. Nigam, N.C. (1983), Introduction to Random Vibrations, MIT Press, Cambridge, MA. p. 360.
  23. Nour, A., Slimani, A., Laouami, N., Afra, H. (2003), "Finite element model for the probabilistic seismic response of heterogeneous soil profile", Soil Dyn Earthquake Engng, Vol. 23, No. 5, pp. 331-348. https://doi.org/10.1016/S0267-7261(03)00036-8
  24. Ostoja-Starzewski, M., (1989), "Wavefront propagation in discrete random media via stochastic Huygens' minor principle", Journal of the Franklin Institute, Vol. 326, No. 2, pp. 281-293. https://doi.org/10.1016/0016-0032(89)90075-6
  25. R Development Core Team (2004), R: a language and environment for statistical computing, R Foundation for Statistical Computing, Vienna, Austria, (http://www.r-project.org).
  26. Rahman, M.S., Yeh, C.H. (1999), "Variability of seismic response of soils using stochastic finite element method", Soil Dyn Earthquake Engng, Vol. 18, pp. 229-245. https://doi.org/10.1016/S0267-7261(98)00031-1
  27. Robertsson, J.O.A, Blanch, J.O., Symes, W.W. (1994), "Viscoelastic finite-difference modeling", Geophysics, Vol. 59, No. 9, pp. 1444-1456. https://doi.org/10.1190/1.1443701
  28. Sahimi, M., Allaei, S.M.V. (2008), "Numerical simulation of wave propagation, Part II: parallel computing", Computing in Science & Engineering, Vol. 10, No. 4, pp. 76-83.
  29. Santamarina, J.C., Fratta, D. (2005), Discrete Signals and Inverse Problems, England: John Wiley & Sons Ltd. p. 350.
  30. Schlather, M. (2001), "Simulation and analysis of random fields", R News, Vol. 1, No. 2, pp. 18-20.
  31. Shapiro, N.M., Campillo, M., Singh, S.K., Pacheco, J. (1998), "Channel seismic waves in the accretionary prism of the middle america trench", Geophys. Res. Lett., Vol. 25, pp. 101-104. https://doi.org/10.1029/97GL03492
  32. Tripathi, J.N., Ram, A. (1997), "Elastic-wave scattering in a random medium characterized by the von karman correlation function and smallscale inhomogeneities in the lithosphere", Geophys. J. Int., Vol. 131, No. 3, pp. 682-698. https://doi.org/10.1111/j.1365-246X.1997.tb06606.x
  33. Villiappan, S., Murti, V. (1984), Finite Element Constraints in the Analysis of Wave Propagation Problem, UNICV Report No. R-218, The University of New South Wales, School of Civil Engineering. p. 48.
  34. Yang, H.H., Hung, S.H. (2005), "Validation of ray and wave theoretical travel-times in heterogeneous random media", Geophys. J. Int., Vol. 32, L20302.
  35. Yi, M.J., Kim, J.H., Chung, S.H. (2003), "Enhancing the resolving power of least-squares inversion with active constraint balancing", Geophysics, Vol. 68, No. 3, pp. 931-941. https://doi.org/10.1190/1.1581045
  36. You, K.H. (2011), "Analysis on the effect of strength improvement and water barrier by tunnel grouting reinforcement", Journal of Korean Tunnelling and Underground Space Association, Vol. 13, No. 4, pp. 291-304.
  37. Zendgui, D., Berrah, M.K., Kausel, E. (1999), "Stochastic deamplification of spatially varying seismic motions", Soil Dyn Earthquake Engng, Vol. 18, No. 6, pp. 409-421. https://doi.org/10.1016/S0267-7261(99)00015-9
  38. Zerva, A., Zervas, V. (2002), "Spatial variation of seismic ground motions: an overview", Applied Mechanical Review, Vol. 55, No. 3, pp. 271-297. https://doi.org/10.1115/1.1458013
  39. Zerwer, A., Cascante, G., Hutchinson, J. (2002), "Parameter Estimation in Finite Element Simulations of Rayleigh Waves", J. Geotech. Geoenviron. Eng., Vol. 128, No. 3, pp. 250-261. https://doi.org/10.1061/(ASCE)1090-0241(2002)128:3(250)
  40. Zhao, L., Jordan, T.H., Chapman, C.H. (2000), "Three-dimensional Frẻchet differential kernels for seismic delay times", Geophys. J. Int., Vol. 141, pp. 558-576. https://doi.org/10.1046/j.1365-246x.2000.00085.x

Cited by

  1. Evaluation of ground characteristics near underground rainfall storage facilities using shear wave velocity vol.16, pp.2, 2014, https://doi.org/10.9711/KTAJ.2014.16.2.225