DOI QR코드

DOI QR Code

Probabilistic Stability Analysis of Slopes by the Limit Equilibrium Method Considering Spatial Variability of Soil Property

지반물성의 공간적 변동성을 고려한 한계평형법에 의한 확률론적 사면안정 해석

  • Received : 2009.03.16
  • Accepted : 2009.11.23
  • Published : 2009.12.31

Abstract

In this paper, a numerical procedure of probabilistic slope stability analysis that considers the spatial variability of soil properties is presented. The procedure extends the deterministic analysis based on the limit equilibrium method of slices to a probabilistic approach that accounts for the uncertainties and spatial variation of the soil parameters. Making no a priori assumptions about the critical failure surface like the Random Finite Element Method (RFEM), the approach saves the amount of solution time required to perform the analysis. Two-dimensional random fields are generated based on a Karhunen-Lo$\grave{e}$ve expansion in a fashion consistent with a specified marginal distribution function and an autocorrelation function. A Monte Carlo simulation is then used to determine the statistical response based on the random fields. A series of analyses were performed to verify the application potential of the proposed method and to study the effects of uncertainty caused by the spatial heterogeneity on the stability of slope. The results show that the proposed method can efficiently consider the various failure mechanisms caused by the spatial variability of soil property in the probabilistic slope stability assessment.

본 연구에서는 확률론적 해석에 지반의 공간적 변동성을 고려하기 위한 해석 절차를 제시하였다. 제안된 방법은 한계평형법을 이용하는 결정론적 해석방법을 지반정수의 불확실성과 공간적 변동성을 고려할 수 있도록 확률론적 사면안정 해석으로 확장한다. 개발된 방법은 랜덤유한요소해석법과 같이 미리 임계파괴면을 가정하지 않으면서도 계산시간을 단축할 수 있다는 장점이 있다. 지정된 입력 확률분포함수와 자기상관함수를 따르는 2차원의 랜덤필드를 생성하기 위하여 Karhunen-Lo$\grave{e}$ve 전개법을 사용하였으며, 생성된 랜덤필드를 이용하여 확률론적 응답을 얻기 위해 Monte Carlo 시뮬레이션을 수행하였다. 개발된 해석기법의 적용성을 검토하고 지반정수의 공간적 변화가 확률론적 안정해석에 미치는 영향을 검토하기 위해 예제해석을 수행하였으며, 해석결과는 제안된 방법이 지반물성의 공간적 변동성에 따른 다양한 사면파괴 형태를 확률론적 사면안정 해석에 효과적으로 고려할 수 있음을 보여준다.

Keywords

References

  1. 김기영, 조성은 (2006), "확률론적 사면안정 해석기법에 관한 연구", 한국지반공학회논문집, 제22권, 11호, pp.101-111
  2. 김주용 (1998), 유한요소법을 이용한 사면안정해석, 박사학위논문, 한국과학기술원
  3. 김진만 (2003), "지반성질 불확실성을 고려한 사면안정 해석", 한국지반공학회 봄학술발표논문집, pp.123-130
  4. 김형배, 이승호 (2002), "실용적인 확률론적 사면안정 해석 기법 개발", 한국지반공학회논문집, 제18권, 5호, pp.271-280
  5. 박혁진, 윤운상, 박성욱, 한병현 등 (2005), "점추정법과 최대우도법을 이용한 암반사면의 파괴확률 산정", 대한토목학회 정기학술대회논문집, pp.4965-4968
  6. 장연수, 오승현, 김종수 (2002), "암반사면의 평면파괴에 대한 신뢰성해석", 한국지반공학회논문집, 제18권, 4호, pp.119-126
  7. 조성은, 박형춘 (2008), "지반의 공간적 변동성을 고려한 확률론적 해석기법에 관한 연구", 한국지반공학회논문집, 제24권, 8호, pp.111-123
  8. 조성은, 변위용 (2007), "인공신경망 기반의 한계상태함수를 이용한 사면의 신뢰성해석", 한국지반공학회논문집, 제23권, 8호, pp.117-127
  9. Alonso, E. E. (1976), "Risk Analysis of Slopes and Its Application to Slopes in Canadian Sensitive Clays", G$\'{e}$otechnique, Vol.26, No.3, pp.453-472 https://doi.org/10.1680/geot.1976.26.3.453
  10. Baecher, G. B., and Christian, J. T. (2003), Reliability and Statistics in Geotechnical Engineering, John Wiley & Sons
  11. Bhattacharya, G., Jana, D., Ojha, S., and Chakraborty, S. (2003), "Direct Search for Minimum Reliability Index of Earth Slopes", Computers and Geotechnics, Vol.30, No.6, pp.455-462 https://doi.org/10.1016/S0266-352X(03)00059-4
  12. Cho, S. E. (2007), "Effects of Spatial Variability of Soil Properties on Slope Stability", Engineering Geology, Vol.92, No.3-4, pp.97-109 https://doi.org/10.1016/j.enggeo.2007.03.006
  13. Cho, S. E. (2009), "Probabilistic Stability Analyses of Slopes Using the ANN-based Response Surface", Computers and Geotechnics, Vol.36, No.5, pp.787-797 https://doi.org/10.1016/j.compgeo.2009.01.003
  14. Christian, J. T., Ladd, C. C., and Baecher, G. B. (1994), "Reliability Applied to Slope Stability Analysis", J. Geotech. Eng. Div., ASCE, Vol.120, No.12, pp.2180-2207 https://doi.org/10.1061/(ASCE)0733-9410(1994)120:12(2180)
  15. DeGroot, D. J., and Baecher, G. B. (1993), "Estimating Autocovariance of In-situ Soil Properties", Journal of the Geotechnical Engineering, Vol.119, No.1, pp.147-166 https://doi.org/10.1061/(ASCE)0733-9410(1993)119:1(147)
  16. Elkateb, T., Chalaturnyk, R., and Robertson P. K. (2002), "An Overview of Soil Heterogeneity: Quantification and Implications on Geotechnical Field Problems", Canadian Geotechnical Journal, Vol.40, No.1, pp.1-15 https://doi.org/10.1139/t02-090
  17. El-Ramly, H., Morgenstern, N. R., and Cruden, D. M. (2002), "Probabilistic Slope Stability Analysis for Practice", Canadian Geotechnical Journal, Vol.39, No.3, pp.665-683 https://doi.org/10.1139/t02-034
  18. El-Ramly, H., Morgenstern, N. R., and Cruden, D. M. (2003), "Probabilistic Stability Analysis of a Tailings Dyke on Presheared Clay-shale", Canadian Geotechnical Journal, Vol.40, No.1, pp. 192-208 https://doi.org/10.1139/t02-095
  19. Ghanem, R. G., and Spanos, P. D. (1991), Stochastic Finite Element-A Spectral Approach, Springer Verlag, New York
  20. Ghiocel, D. M., and Ghanem, R. G. (2002), "Stochastic Finiteelement Analysis of Seismic Soil-structure Interaction", Journal of Engineering Mechanics, ASCE, Vol.128, No.1, pp.66-77 https://doi.org/10.1061/(ASCE)0733-9399(2002)128:1(66)
  21. Griffiths, D. V., and Fenton G. A. (2004), "Probabilistic Slope Stability Analysis by Finite Elements", Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol.130, No.5, pp.507-518 https://doi.org/10.1061/(ASCE)1090-0241(2004)130:5(507)
  22. Griffiths, D. V., Huang, J., and Fenton, G. A. (2009), "Influence of Spatial Variability on Slope Reliability using 2-d Random Fields", Journal of Geotechnical and Geoenvironmental Engineering, ASCE, dx.doi.org/10.1061/(ASCE)GT.1943-5606.0000126
  23. Hassan, A. M., and Wolff, T. F. (1999), "Search Algorithm for Minimum Reliability Index of Earth Slopes", Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol.125, No.4, pp.301-308 https://doi.org/10.1061/(ASCE)1090-0241(1999)125:4(301)
  24. Hicks, M. A., and Onisiphorou, C. (2005), "Stochastic Evaluation of Static Liquefaction in a Predominantly Dilative Sand Fill", G$\'{e}$otechnique, Vol.55, No.2, pp.123-133 https://doi.org/10.1680/geot.2005.55.2.123
  25. Hong, H. P., and Roh, G. (2008), "Reliability Evaluation of Earth Slopes", Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol.134, No.12, pp.1700-1705 https://doi.org/10.1061/(ASCE)1090-0241(2008)134:12(1700)
  26. Hsu, S. C., and Nelson, P. P. (2006), "Material Spatial Variability and Slope Stability for Weak Rock Masses", Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol.132, No.2, pp.183-193 https://doi.org/10.1061/(ASCE)1090-0241(2006)132:2(183)
  27. Lacasse, S, and Nadim, F. (1996), 'Uncertainties in Characterizing Soil Properties', Uncertainty in the Geologic Environment: From theory to practice, (eds Shackleford, CD, Nelson, PP and Roth, MJS.), Geotechnical Special Publication, ASCE, No. 58, pp. 49-75
  28. Li, K. S., and Lumb, P. (1987), "Probabilistic Design of Slopes", Canadian Geotechnical Journal, Vol.24, No.4, pp.520-535 https://doi.org/10.1139/t87-068
  29. Low, B. K. (2003), "Practical Probabilistic Slope Stability Analysis", 12th Panamerican Conference on Soil Mechanics and Geotechnical Engineering and 39th U.S. Rock Mechanics Symposium, MIT, Cambridge, Massachusetts, Vol.2, pp.2777-2784
  30. Matthies, G., Brenner, C., Bucher, C., and Soares, C(1997), "Uncertainties in Probabilistic Numerical Analysis of Structures and Solids-stochastic Finite Elements", Structural Safety, Vol.19, No.3, pp.283-336 https://doi.org/10.1016/S0167-4730(97)00013-1
  31. Mostyn, G. R., and Li, K. S. (1993), "Probabilistic Slope Stability-State of Play", Conference on Probabilistic Methods in Geotechnical Engineering, Li and Lo (eds.), Balkema, Rotterdam, The Netherlands, pp.89-110
  32. Rackwitz, R. (2000), "Reviewing Probabilistic Soils Modeling", Computers and Geotechnics, Vol.26, No.3, pp.199-223 https://doi.org/10.1016/S0266-352X(99)00039-7
  33. Spanos, P. D., and Ghanem, R. G. (1989), "Stochastic Finite Element Expansion for Random Media", Journal of Engineering Mechanics, ASCE, Vol.115, No.5, pp.1035-1053 https://doi.org/10.1061/(ASCE)0733-9399(1989)115:5(1035)
  34. Stein, M. L. (1987), "Large Sample Properties of Simulations Using Latin Hypercube Sampling", Technometrics, Vol.29, No.2, pp.143-151 https://doi.org/10.2307/1269769
  35. Sudret, B., and Der Kiureghian, A. (2000), Stochastic Finite Element Methods and Reliability: a State-of-the-art Report, Tech. Rep. Report No. UCB/SEMM-2000/08, Department of Civil & Environmental Engineering, University of California, Berkeley, Institute of Structural Engineering, Mechanics and Materials
  36. Vanmarcke, E. H. (1977), "Reliability of Earth Slopes", J. Geotech. Eng. Div., ASCE, Vol.103, No.11, pp.1247-1265
  37. Vanmarcke, E. H. (1983), Random fields: Analysis and Synthesis, The MIT Press, Cambridge, MA