A Study on the Factor of Safety for Rock Slopes Based on Three Dimensional Effects

Og-Geon Seo; Seung-Ho Lee

doi:10.7843/kgs.2014.31.1.47

All Issue

2015 Vol.31, Issue 1 Preview Page Next Page

A Study on the Factor of Safety for Rock Slopes Based on Three Dimensional Effects 3차원 효과를 고려한 암반사면의 안전율 변화에 관한 연구

31 January 2015. pp. 47-52

PDF XML

Abstract

In the slope stability analysis and design, Limit Equilibrium Method (LEM) and Shear Strength Reduction technique (SSR) are mainly used. Both methods are able to perform two and three dimensional analysis. SSR is considered to be more sensitive and more reasonable than LEM by many researchers. However, in practice LEM is still widely used because of the increase of analysis time and complexity of the model in SSR. In this study, three dimensional analysis of the protruding rock slope is performed by SSR in order to study the effects of protruding length using rock slope FLAC 3D. In this study, as results of analysis variations of the safety factor have been studied according to slope angle, slope height, the soil strength, protruding slope length projected variables. The results show that the factor of safety as more affected by the shapes of the protruding rock slope than the rock strength.

Keywords

3D Slope Stability

Rock Slope

LEM

SSR

Factor of Safety

FLAC 3D

사면안정분야의 해석과 설계에는 한계평형법(LEM)과 전단강도 감소기법(SSR)이 주로 사용된다. 이 두 방법은 2차원과 3차원 해석을 모두 수행할 수 있지만 많은 연구자들에 의해 전단강도 감소기법이 해석 변수에 대해 더욱 민감하게 반응하고 합리적인 결과를 산출한다고 알려져있다. 그러나 전단강도 감소기법의 모델링의 복잡함과 해석시간의 증가 등의 이유로 현계평형법이 여전히 일반적으로 사용되고 있다. 본 연구에서는 FLAC 3D를 사용하여 전단강도 감소기법을 통한 돌출된 암반사면의 3차원 효과에 대해 연구하였다. 수치해석 변수는 사면의 경사, 높이, 지반강도, 사면의 돌출길이이며 연구 결과 사면의 안전율은 암반의 강도보다 사면의 형상에 더 영향을 받는 것으로 나타났다.

References

1.Bishop, A. W. (1955), The Use of the Slip Circle in the Stability Analysis of Slopes, Institution of Civil Engineers.

2.Cala, M. and Flisiak, J. (2001), “Slope Stability Analysis with FLAC and Limit Equilibrium Methods”, In FLAC and Numerical Modeling in Geomechanics-2001, Proceedings of the 2nd International FLAC Symposium on Numerical Modeling in Geomechanics, Ecully- Lyon, France, pp.113-114.

3.Chen, Z., Mi, H., Zhang, F., and Wang, X. (2003), “A Simplified Method for 3D Slope Stability Analysis”, Canadian Geotechnical Journal, Vol.40, No.3, pp.675-683.

4.Dawson, E. M. and Roth, W. H. (1999), “Slope Stability Analysis with FLAC”, In FLAC and Numerical Modeling in Geomechanics, Proceedings of the International FLAC Symposium on Numerical Modeling in Geomechanics, Minneapolis, Minnesota, pp.3-9.

5.Duncan, J. M. (1996), “State of the Art: Limit Equilibrium and Finite-element Analysis of Slopes”, Journal of Geotechnical Engineering, Vol.122, No.7, pp.577-596.

6.Fellenius, W. (1927), Erdstatische Berechnungen, Revised Edition, W. Ernst u. Sons.

7.Griffiths, D.V. G.L. and Lane, P.A. (1999), “Slope Stability Analysis by Finite Elements”, Geotechnique, Vol.49, No.3, pp.387-403.

8.Janbu, N., Bjerrum, L., and Kjaernsli, B. (1956), “Soil Mechanics Applied to Some Engineering Problems”, Norwegian Geotechnical Institute, Publication, 16.

9.Jiang, G. L. and Magnan, J. P. (1997), “Stability Analysis of Embankments: Comparison of Limit Analysis with Method of Slices”, Geotechnique, Vol.47, No.4, pp.857-872.

10.Lam, L. and Fredlund, D. G. (1993), A General Limit Equilibrium Model for Three-dimensional Slope Stability Analysis”, Canadian Geotechnical Journal, Vol.30, No.6, pp.905-919.

Information

Publisher :The Korean Geotechnical Society
Publisher(Ko) :한국지반공학회
Journal Title :Journal of the Korean Geotechnical Society
Journal Title(Ko) :한국지반공학회 논문집
Volume : 31
No :1
Pages :47-52
Received Date : 2014-11-20
Revised Date : 2015-01-12
Accepted Date : 2015-01-19
DOI :https://doi.org/10.7843/kgs.2014.31.1.47

Journal of the Korean Geotechnical Society ISSN:1229-2427(Print) 2288-646X(Online) 한국지반공학회 논문집

All Issue