Browse > Article
http://dx.doi.org/10.12989/gae.2022.28.6.637

Evaluation of unsaturated soil slope stability by incorporating soil-water characteristic curve  

Zhai, Qian (Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education, Bridge Engineering Research Center of Southeast University, Southeast University)
Tian, Gang (Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education, Bridge Engineering Research Center of Southeast University, Southeast University)
Ye, Weimin (Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University)
Rahardjo, Harianto (School of Civil and Environmental Engineering, Nanyang Technological University)
Dai, Guoliang (Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education, Bridge Engineering Research Center of Southeast University, Southeast University)
Wang, Shijun (Economy & Technology Research Institute, Gansu Electric Power Corporation)
Publication Information
Geomechanics and Engineering / v.28, no.6, 2022 , pp. 637-644 More about this Journal
Abstract
Loess soils are unsaturated and widely distributed in the northwest zone in China. Many steep slope of unsaturated are observed are observed to be naturally stable. However, a low factor of safety (FoS) for these slopes would be computed from the slope stability analysis following local code practices. It seems that the analyzed results following the local code practices do not agree with the real condition as observed in the field. It is commonly known that soil suction plays an important role in slope stability due to a higher shear strength of the unsaturated soil as compared with that of the saturated soil. In this paper, it is observed that the computed FoS can also be affected by unsaturated unit weight of the soil. However, the effect of unsaturated unit weight of the soil on the slope stability is commonly ignored in engineering practice. Therefore, both the effects of shear strength and unit weight of the unsaturated soil on the computed FoS of unsaturated soil slope are investigated in this study. It is observed that the unsaturated unit weight of soil on the computed FoS increases with increase in slope angle. It is also observed that the effects of the unsaturated shear strength and unsaturated unit weight on the computed FoS are more significant than the effect of 3D analyses compared to the 2D analyses on the FoS.
Keywords
shear strength; slope stability; soil-water characteristic curve; unit weight; unsaturated soil;
Citations & Related Records
Times Cited By KSCI : 10  (Citation Analysis)
연도 인용수 순위
1 Fredlund, D.G. and Fredlund, M.D. (2020), "Keynote Lecture: Developments in landslide analysis", Geotechnics for Sustainable Infrastructure Development (Vol. 62, pp. 777-794). Springer-Verlag Singapore Pte Ltd. https://doi.org/10.1007/978-981-15-2184-3_101.   DOI
2 Sengani, F., Muavhi, N. and Mulenga, F. (2021), "Advanced analysis of road-slope stability in a brittle and faulted rockmass terrain by several techniques", Transportation Geotech., 28, Article 100545. https://doi.org/10.1016/j.trgeo.2021.100545.   DOI
3 Tran An, T.P., Kim, A.R. and Cho, G.C. (2019), "Numerical modeling on the stability of slope with foundation during rainfall", Geomech. Eng., 17(1), 109-118. https://doi.org/10.12989/gae.2019.17.1.109.   DOI
4 Vanapalli, S.K., Fredlund, D.G., Pufahl, D.E. and Clifton, A.W. (1996), "Model for the prediction of shear strength with respect to soil suction", Can. Geotech. J., 33(3), 379-392. https://doi.org/10.1139/t96-060.   DOI
5 Zhai, Q., Rahardjo, H., Satyanaga, A. and Dai, G. (2019), "Estimation of unsaturated shear strength from soil-water characteristic curve", Acta Geotechnica, 14(6), 1977-1990. https://doi.org/10.1007/s11440-019-00785-y.   DOI
6 Fellenius, W. (1936), "Calculation of the Stability of Earth Dams", Trans. 2nd Int. Cong. Large Dams, Washington, 445-459.
7 Zhao, L., Xia, P., Xie, R., Li, L., Zhang, Y. and Cheng, X. (2017), "Stability analysis of homogeneous slopes with benches", Geomech. Eng., 13(3), 517-533. https://doi.org/10.12989/gae.2017.13.3.517.   DOI
8 Arief, M., Widodo, N.P. and Prassetyo, S. (2020), "Study of slope geometry effect on 2D and 3D slope stability analysis using equilibrium method", Indonesian Min. Professionals J., 2(1), 6. https://doi.org/10.36986/impj.v2i1.27.   DOI
9 Azarafza, M., Akgun, H. and Asghari-Kaljahi, E. (2017), "Assessment of rock slope stability by slope mass rating (SMR): A case study for the gas flare site in Assalouyeh, South of Iran", Geomech. Eng., 13(4), 571-584. https://doi.org/10.12989/gae.2017.13.4.571.   DOI
10 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   DOI
11 Fredlund, D.G., Morgenstern, N.R. and Widger, R.A. (1978), "Shear-strength of unsaturated soils", Can. Geotech. J., 15(3), 313-321. https://doi.org/10.1139/t78-029.   DOI
12 Ghadrdan, M., Shaghaghi, T. and Tolooiyan, A. (2020), "Sensitivity of the stability assessment of a deep excavation to the material characterisations and analysis methods", Geomechanics and Geophysics for Geo-Energy and Geo-Resources, 6(4), Article 59. https://doi.org/10.1007/s40948-020-00186-6.   DOI
13 Leong, E.C. and Rahardjo, H. (2012), "Two and three-dimensional slope stability reanalyses of Bukit Batok slope", Comput. Geotech., 42, 81-88. https://doi.org/10.1016/j.compgeo.2012.01.001.   DOI
14 Janbu, N. (1954), "Application of composite slip surfaces for stability analysis", Paper presented at the Proceedings of the European Conference on Stability Analysis, Stockholm, Sweden.
15 Fredlund, D.G. and Xing, A.Q. (1994), "Equations for the soil-water characteristic curve", Can. Geotech. J., 31(4), 521-532. https://doi.org/10.1139/t94-061.   DOI
16 Gasmo, J., Rahardjo, H. and Leong, E.C. (2000), "Infiltration effects on stability of a residual soil slope", Comput. Geotech., 26(2), 145-165.   DOI
17 Hassanikhah, A. andDrumm, E.C. (2020), "Stability and evolution of planar and concave slopes under unsaturated and rainfall conditions", Int. J. Geomech., 20(7), Article 04020099. https://doi.org/10.1061/(asce)gm.1943-5622.0001662.   DOI
18 Lizarraga, J. and Buscarnera, G. (2018), "Safety factors to detect flowslides and slips in unsaturated shallow slopes", Geotechnique, 68(5), 442-450.   DOI
19 Morgenstern, N.R. and Price, V.E. (1965). "The analysis of the stability of general slip surfaces", Geotechnique, 15(1), 79-93. https://doi.org/10.1680/geot.1965.15.1.79.   DOI
20 Sengani, F. and Mulenga, F. (2020), "Application of limit equilibrium analysis and numerical modeling in a case of slope instability". Sustainability, 12(21), Article 8870. https://doi.org/10.3390/su12218870.   DOI
21 Mehdipour, I., Ghazavi, M. and Moayed, R.Z. (2017), "Stability analysis of geocell-reinforced slopes using the limit equilibrium horizontal slice method", Int. J. Geomech., 17(9), Article 06017007. https://doi.org/10.1061/(asce)gm.1943-5622.0000935.   DOI
22 Peranic, J., Arbanas, S.M. and Arbanas, Z. (2021), "Importance of the unsaturated zone in landslide reactivation on flysch slopes: observations from Valici Landslide, Croatia", Landslides. https://doi.org/10.1007/s10346-021-01757-8   DOI
23 Singh, A.K., Kundu, J. and Sarkar, K. (2018), "Stability analysis of a recurring soil slope failure along NH-5, Himachal Himalaya, India", Nat. Hazards, 90(2), 863-885. https://doi.org/10.1007/s11069-017-3076-z.   DOI
24 Tsai, T.L. and Chen, H.F. (2010), "Effects of degree of saturation on shallow landslides triggered by rainfall", Environ. Earth Sci., 59(6), 1285-1295.   DOI
25 Terzaghi, K., Peck, R.B. and Mesri, G. (1996), "Soil mechanics", New York: John Wiley & Sons.