The Effects of Longitudinal Dimension in Three Dimensional Slope Stability Analysis

Document Type : Technical Notes

Authors

1 Ph.D. Instructor, Research Scholar, National Institute of Technology, Patna, India.

2 Assistant Professor, Department of Civil Engineering, National Institute of Technology, Patna, India.

3 Associate Professor, Department of Civil Engineering, National Institute of Technology, Patna, India.

Abstract

Of late, three dimensional slope stability analysis has gained popularity among the geotechnical engineers so that the actual response of slope failure, which essentially occurs in 3D, can be captured. However, three dimensional slope failure analysis necessitates the proper consideration of the third/longitudinal dimension of the slope. Three dimensional slope stability analysis can yield erroneous results if inadequate length of the third dimension of the slope is used during analysis. This study employs Bishop’s simplified approach to find the minimum length of a 3D soil slope’s third/longitudinal direction to be considered during analysis. A parametric study compares the findings of 3D and 2D analyses for different geometries, pore pressure ratios and seismic loading for a cohesive-frictional slope. A total of 15 loading cases have been analyzed to study the convergence behavior of the 3D and 2D Factor of Safety (FS) values for slopes with different inclination angles and longitudinal length-to-height (l/h) ratios. The results presented in this study dictate that the longitudinal/third dimension of a 3D slope model should be at least five times the slope’s height for accurate 3D slope analysis. For all loading situations, whether a slope will collapse at the base or toe and the failure mass volumes are estimated. As the base inclination angle increases for a particular slope, the type of failure gradually shifts from base failure to toe failure. The volume of failure mass is seen to follow a decreasing trend with an increase in the slope angle.

Keywords

Main Subjects


Arai, K. and Tagyo, K. (1985). "Determination of noncircular slip surface giving the minimum factor of safety in slope stability analysis", Soils and Foundations, 25(1), 43-51, https://doi.org/10.3208/sandf1972.25.43.
Arellano, D. and Stark, T.D. (2000). "Importance of three-dimensional slope stability analyses in practice", In Proceedings of Sessions of Geo-Denver 2000-Slope Stability 2000, (Vol. 289, pp. 18-32), https://doi.org/10.1061/40512(289)2.
Baligh, M.M. and Azzouz, A.S. (1975). "End effects on stability of cohesive slopes", ASCE Journal of the Geotechnical Engineering Division, 101(11), 1105-1117, https://doi.org/10.3313/jls1964.23.16.
Bishop, A.W. (1955). "The use of the slip circle in the stability analysis of slopes", Geotechnique, 5(1), 7-17, https://doi.org/10.1680/geot.1955.5.1.7.
Cavounidis, S. (1988). "An extension of Bishop's simplified method of slope stability analysis to three dimensions", Geotechnique, 38(1), 155-156, https://doi.org/10.1680/geot.1988.38.1.155.
Chakraborty, A. and Goswami, D. (2021). "Three-dimensional (3D) slope stability analysis using stability charts", International Journal of Geotechnical Engineering, 15(5), 642-649, https://doi.org/10.1080/19386362.2018.145743.
Chugh, A.K. (2003). "On the boundary conditions in slope stability analysis", International Journal for Numerical and Analytical Methods in Geomechanics, 27(11), 905926, https://doi.org/10.1002/nag.305.
Cornforth, D.H. (2005). Landslides in practice, Jhon Wiley & Sons, New Jersey.
Dawson, E.M. and Roth, W.H. (1999). Slope stability analysis with FLAC, In FLAC and Numerical Modeling in Geomechanics, (pp. 3-9), CRC Press, https://doi.org/10.1201/9781003078531-2.
Deng, D., Zhao, L. and Li, L. (2015). "Limit equilibrium slope stability analysis using the nonlinear strength failure criterion", Canadian Geotechnical Journal, 52(5), 563-576, https://doi.org/10.1139/cgj-2014-0111.
Duncan, J.M. (1996). "State of the art: limit equilibrium and finite-element analysis of slopes", Journal of Geotechnical Engineering, 122(7), 577-596, https://doi.org/10.1061/(ASCE)0733-9410(1996)122:7(577).
He, Y., Liu, Y., Zhang, Y. and Yuan, R. (2019). "Stability assessment of three-dimensional slopes with cracks", Engineering Geology, 252, 136-144, https://doi.org/10.1016/j.enggeo.2019.03.001.
Huang, C.C., Tsai, C.C. and Chen, Y.H. (2002). "Generalized method for three-dimensional slope stability analysis", Journal of Geotechnical and Geoenvironmental Engineering, 128(10), 836-848, https://doi.org/10.1061/(asce)10900241(2002)128:10(836).
Janbu, N. (1973). Slope stability computations, Wiley (John) & Sons, Incorporated, https://doi.org/10.1016/0148-9062(75)90139-4.
Johari, A. and Mousavi, S. (2019). "An analytical probabilistic analysis of slopes based on limit equilibrium methods", Bulletin of Engineering Geology and the Environment, 78, 4333-4347, https://doi.org/10.1007/s10064-018-1408-1.
Kalantari, B. and Pourkhosravani, A. (2011). "A review of current methods for slope stability evaluation", Electronic Journal of Geotechnical Engineering, 16, 1245-1254.
Komasi, M. and Beiranvand, B. (2021). "Seepage and stability analysis of the Eyvashan Earth Dam under drawdown conditions", Civil Engineering Infrastructures Journal, 54(2), 205-223, https://doi.org/10.22059/ceij.2020.293429.1634.
Kumar, S., Choudhary, S.S. and Burman, A. (2023a). "Recent advances in 3D slope stability analysis: A detailed review", Modeling Earth Systems and Environment, 9(2), 14451462, https://doi.org/10.1007/s40808-022-01597-y.
Kumar, S., Choudhary, S.S. and Burman, A. (2023b). "The effect of slope height and angle on the safety factor and modes of failure of 3D slopes analysis using limit equilibrium method", Beni-Suef University Journal of Basic and Applied Sciences, 12(1), 84, https://doi.org/10.1186/s43088-023-00423-3.
Li, A.J., Merifield, R.S. and Lyamin, A.V. (2010). "Three-dimensional stability charts for slopes based on limit analysis methods", Canadian Geotechnical Journal, 47(12), 1316-1334. https://doi.org/10.1139/T10-030.
Lin, H.D., Wang, W.C. and Li, A.J. (2020). "Investigation of dilatancy angle effects on slope stability using the 3D finite element method strength reduction technique", Computers and Geotechnics, 118, 103295, https://doi.org/10.1016/j.compgeo.2019.103295.
Liu, X., Li, D.Q., Cao, Z.J. and Wang, Y. (2020). "Adaptive Monte Carlo simulation method for system reliability analysis of slope stability based on limit equilibrium methods", Engineering Geology, 264, 105384, https://doi.org/10.1016/j.enggeo.2019.105384.
Lorig, L. (1999). Lessons learned from slope stability studies, In FLAC and Numerical Modeling in Geomechanics, (pp.1722), CRC Press, https://doi.org/10.1201/9781003078531-4.
Loukidis, D., Bandini, P. and Salgado, R. (2003). "Comparative study of limit equilibrium, limit analysis and finite element analysis of the seismic stability of slopes", Geotechnique, 53(5), 463-479, https://doi.org/10.1007/s12040-019-1314-3.
Lyamin, A.V. and Sloan, S.W. (2002). "Lower bound limit analysis using non‐linear programming", International Journal for Numerical Methods in Engineering, 55(5), 573-611, https://doi.org/10.1002/nme.511.
Michalowski, R.L. (2002). "Stability charts for uniform slopes", Journal of Geotechnical and Geoenvironmental Engineering, 128(4), 351-355, https://doi.org/10.1061/(ASCE)1090-0241(2002)128:4(351).
Michalowski, R.L. (2010). "Limit analysis and stability charts for 3D slope failures",  Journal of Geotechnical and Geoenvironmental Engineering, 136(4), 583593, https://doi.org/10.1061/(asce)gt.1943- 5606.0000251.
Qi, S., Ling, D., Yao, Q., Lu, G., Yang, X. and Zhou, J.W. (2021). "Evaluating slope stability with 3D limit equilibrium technique and its application to landfill in China", Engineering Geology, 280, 105939, https://doi.org/10.1016/j.enggeo.2020.105939.
Qian, Z. G., Li, A.J., Chen, W.C., Lyamin, A.V. and Jiang, J.C. (2019). "An artificial neural network approach to inhomogeneous soil slope stability predictions based on limit analysis methods",  Soils and Foundations, 59(2), 556-569, https://doi.org/10.1016/j.sandf.2018.10.008.
Qin, C.B., Chian, S.C. and Gazetas, G. (2019). "Kinematic analysis of seismic slope stability with discretisation technique and pseudo-dynamic approach: A new perspective", Geotechnique, 69(11), 1031-1033,   https://doi.org/10.1680/jgeot.18.D.011.
Rao, B., Burman, A. and Roy, L.B. (2023). "An efficient box search method for limit equilibrium method-based 3D slope stability analysis", Transportation Infrastructure Geotechnology, 11(1), 327-358, https://doi.org/10.1007/s40515-023-00285-3
Reid, M.E., Christian, S.B., Brien, D.L. and Henderson, S. (2015). Scoops3D-software to analyze three-dimensional slope stability throughout a digital landscape, (No. 14-A1),  U.S. Geological Survey.
Soralump, S., Panthi, K. and Prempramote, S. (2021). "Assessment of the upstream slope failure of a dam due to repeated cyclic drawdown", Soils and Foundations, 61(5), 13861398, https://doi.org/10.1016/j.sandf.2021.08.006.
Su, Z. and Shao, L. (2021). "A three-dimensional slope stability analysis method based on finite element method stress analysis", Engineering Geology, 280, 105910, https://doi.org/10.1016/j.enggeo.2020.105910.
Tozato, K., Dolojan, N.L. J., Touge, Y., Kure, S., Moriguchi, S., Kawagoe, S., Terada, K. (2022). "Limit equilibrium method-based 3D slope stability analysis for wide area considering influence of rainfall", Engineering Geology, 308, 106808, https://doi.org/10.1016/j.enggeo.2022.106808.
Wang, L., Sun, D. and Li, L. (2019). "Three-dimensional, stability of compound slope using limit analysis method", Canadian Geotechnical Journal, 56(1), 116-125, https://doi.org/10.1139/cgj-2017-0345.
Wang, L., Sun, D., Yao, Y., Wu, L. and Xu, Y. (2020). "Kinematic limit analysis of three-dimensional unsaturated soil slopes reinforced with a row of piles", Computers and Geotechnics, 120, 103428, https://doi.org/10.1016/j.compgeo.2019.103428.
Xie, M., Esaki, T., Qiu, C. and Wang, C. (2006). Geographical information system-based computational implementation and application of spatial three-dimensional slope stability analysis", Computers and Geotechnics, 33(4-5), 260-274, https://doi.org/10.1016/j.compgeo.2006.07.003.
Xu, Y., Zhao, M. wei, Lu, J., Wang, C., Jiang, L., Yang, C. and Huang, X.l. (2022). "Methods for the construction of DEM is of artificial slopes considering morphological features and semantic information", Journal of Mountain Science, 19(2), 563-577, https://doi.org/10.1007/s11629-021-6831-2.
Yuan, W.H., Liu, K., Zhang, W., Dai, B. and Wang, Y. (2020). "Dynamic modeling of large deformation slope failure using smoothed particle finite element method", Landslides, 17(7), 1591-1603, https://doi.org/10.1007/s10346-020-01375-w.
Zheng, Y., Chen, C., Liu, T., Zhang, H., Xia, K. and Liu, F. (2018). "Study on the mechanisms of flexural toppling failure in anti-inclined rock slopes using numerical and limit equilibrium models", Engineering Geology, 237, 116-128, https://doi.org/10.1016/j.enggeo.2018.02.006.