The Journal of Engineering Geology (지질공학)

The Korean Society of Engineering Geology (대한지질공학회)
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Probabilistic Stability and Sensitivity Analysis for a Failed Rock Slope using a Monte Carlo Simulation

몬테카를로시뮬레이션 기법을 이용한 붕괴 암반사면의 확률론적 안정해석 및 민감도 분석

  • Park, Sung-Wook (Department of Geoinformation Engineering, Sejong University) ;
  • Park, Hyuck-Jin (Department of Geoinformation Engineering, Sejong University)
  • 박성욱 (세종대학교 지구정보공학과) ;
  • 박혁진 (세종대학교 지구정보공학과)
  • Received : 2010.11.17
  • Accepted : 2010.12.14
  • Published : 2010.12.31
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Abstract

A probabilistic analysis of slope stability is an appropriate solution in dealing with uncertainty in problems related to engineering geology. In this study, a Monte Carlo simulation was performed to evaluate the performance function that is Barton's equation. A large number of randomly generated values were obtained for random variables, and the performance function was calculated repeatedly using randomly generated values. A previous study provided information of slope geometry and the random characteristics of random variables such as JRC and JCS. The present approach was adopted to analyze two failed slopes. The probabilities of failure were evaluated for each slope, and sensitivity analysis was performed to assess the influence of each random variable on the probability of failure. The analysis results were then compared with the results of a deterministic analysis, indicating that the probabilistic analysis yielded reliable results.

확률론적 해석기법은 사면안정해석을 포함한 다양한 지질공학적인 문제에 내재하는 불확실성을 고려할 수 있는 효과적인 방안으로서 유용한 것으로 알려져 있다. 본 연구에서는 확률변수에 대한 무작위 추출을 통해 상태함수인 한계평형식의 안전율을 반복하여 구하는 몬테카를로시뮬레이션 기법을 이용하여 2개의 암반사면에 대해 확률론적 안정해석을 수행하였다. 본 연구에서 사용된 JRC와 JCS 같은 강도정수 등의 확률변수와 사면의 제원은 선행연구과정을 통해 도출된 값을 사용하였으며, 상태함수는 Barton의 경험식을 활용하였다. 본 연구에서는 각 사면별 파괴확률을 계산하고 이에 대한 민감도 및 신뢰성해석을 수행하였다. 특히 기존 결정론적 방법과의 비교와 샘플링 추출 기법에 대한 분석을 수행하였으며 분석결과 기준값보다 높은 파괴확률이 산정되어 사면의 붕괴이력과 부합되는 결과가 도출되었다. 또한 결정론적인 방법에 비해 변동성이 낮은 결과가 도출되어 해석의 신뢰성이 높은 것으로 나타났다.

Keywords

References

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