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Effect of Slope Angle on the Stability of a Slope Under Rainfall Infiltration

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Abstract

The most devastating factor for slope failures is rainfall infiltration. Surficial slope failures in residual soil slopes are a common sight. In general, slope angles vary considerably from being flat to steep in natural conditions, which govern the hydrological regime of the slope. Further, different types of soils behave differently under rainfall condition in terms of rainfall infiltration and the associated changes in their mechanical behaviour, particularly under different slope inclinations. This paper presents a study on the effect of slope inclination on stability of different soil slopes under rainfall conditions. Two-dimensional numerical models were prepared with three different soils having different hydraulic and mechanical properties to investigate the stability of the unsaturated soil slopes. Seepage analysis is performed in the finite element framework, and stability analysis for the slopes is performed in limit equilibrium framework using numerical package SLIDE. The water table in the slope rises high for flat slopes, which is contrary to levels observed in steep slopes. From the results, it was observed that flat slopes allowed more infiltration leading to the rapid reduction in negative pore pressure thereby decreasing the safety factor. Both the initial factor of safety and minimum factor of safety decreased nonlinearly with slope angle. The critical slip surface becomes shallower (shifts towards the slope surface) with increase in angle of the slope. There was very little influence of slope inclination on the stability for slopes higher than 55°.

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References

  1. Ng CWW, Shi Q (1998) A numerical investigation of the stability of unsaturated soil slopes subjected to transient seepage. Comput Geotech 22(1):1–28

    Article  Google Scholar 

  2. Gasmo JM, Rahardjo H, Leong EC (2000) Infiltration effects on stability of a residual soil slope. Comput Geotech 26(2):145–165

    Article  Google Scholar 

  3. Tsaparas I, Rahardjo H, Toll DG (2002) Controlling parameters for rainfall-induced landslides. Comput Geotech 29:1–27

    Article  Google Scholar 

  4. Rahardjo H, Ong TH, Rezaur RB, Leong EC (2007) Factors controlling instability of homogeneous soil slopes under rainfall. J Geotech Geoenviron Eng. https://doi.org/10.1061/(ASCE)1090-0241(2007)133:12(1532)

    Article  Google Scholar 

  5. Rahimi A, Rahardjo H, Leong EC (2010) Effect of hydraulic properties of soil on rainfall-induced slope failure. Comput Geotech 114(3):135–143

    Google Scholar 

  6. Rocscience Inc. SLIDE v8. (2018) Toronto, Canada: Rocscience Inc

  7. Zhang LL, Zhang J, Zhang LM, Tang WH (2011) Stability analysis of rainfall-induced slope failure—a review. Geotech Eng ICE Proc 164(5):299–316

    Article  Google Scholar 

  8. Rahardjo H, Satyanaga A, Leong EC, Ng YS (2012) Variability of residual soil properties. J Eng Geol 141–142:124–140

    Article  Google Scholar 

  9. Lin H, Zhong W (2018) Influence of rainfall intensity and its pattern on the stability of unsaturated soil slope. Geotech Geol Eng. https://doi.org/10.1007/s10706-018-0631-7

    Article  Google Scholar 

  10. Filho AO, Fernandes AM (2018) Landslide analysis of unsaturated soil slopes based on rainfall and matric suction data. Bull Eng Geol Environ 15:12. https://doi.org/10.1007/s10064-018-1392-5

    Article  Google Scholar 

  11. Bhattacherjee D, Vishwanadham BVS (2018) Effect of geocomposite layers on slope stability under rainfall condition. Indian Geotechnol J 48(2):316–326

    Article  Google Scholar 

  12. Elkamhawy E, Wang H, Zhou B, Yang Z (2018) Failure mechanism of a slope with a thin soft band triggered by intensive rainfall. Environ Earth Sci 77(340):1–15

    Google Scholar 

  13. Vahedifard F, Leshchinsky D, Mortezaei K, Lu N (2016) Effective stress-based limit-equilibrium analysis for homogeneous unsaturated slopes. Int J Geomech. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000554

    Article  Google Scholar 

  14. Yubonchit S, Chinkulkijniwat A, Horpibulsuk S, Jothityangkoon C, Arulrajah A, Suddeepong A (2016) Influence factors involving rainfall-induced shallow slope failure-numerical study. Int J Geomech. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000865

    Article  Google Scholar 

  15. Fenton GA, Hicks MA, Wang X, Griffiths, DV (2013) Effect of slope height and gradient on failure probability. Geocongress, ASCE, 972-981

  16. Mathew J, Kundu S, Kumar KV, Pant CC (2015) Hydrologically complemented deterministic slope stability analysis in part of Indian lesser Himalaya. Geomat Nat Hazards Risk 7(5):1557–1576

    Article  Google Scholar 

  17. Qian ZG, Li AJ, Merifeld RS, Lyamin AV (2014) Slope stability charts for two-layered purely cohesive soils based on finite-element limit analysis methods. Int J Geomech ASCE 15(3):1–14

    Google Scholar 

  18. Gavin K, Xue J (2008) A simple method to analyze infiltration into unsaturated soil slopes. Comput Geotech 35(2):223–230

    Article  Google Scholar 

  19. Childs EC, Collis-George N (1950) The permeability of porous material. Proc R Soc Lond A 201:392–405

    Article  Google Scholar 

  20. Fredlund DG, Rahardjo H (1993) Unsaturated soil mechanics. Wiley, New York

    Book  Google Scholar 

  21. Van Genuchten MT (1980) A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Sci Soc Am J 44:892–898

    Article  Google Scholar 

  22. Mualem Y (1976) Hysteretical models for prediction of the hydraulic conductivity of unsaturated porous media. Water Resour Res 12(6):1248–1254

    Article  Google Scholar 

  23. Fredlund DG, Morgenstern NR, Widger RA (1978) The shear strength of unsaturated soils. Can Geotech J 15(3):313–321

    Article  Google Scholar 

  24. Bishop AW (1955) The use of the slip circle in the stability analysis of slopes. Geotechnique 5(1):7–17

    Article  Google Scholar 

  25. Spencer E (1967) A method of analysis of the stability of embankments assuming parallel inter-slice forces. Geotechnique 17(1):11–26

    Article  Google Scholar 

  26. Morgenstern NR, Price VE (1965) The analysis of the stability of general slip surfaces. Geotechnique 15(1):79–93

    Article  Google Scholar 

  27. Malkawi AIH, Hassan WF, Sarma SK (2001) Global search method for locating general slip surface using Monte Carlo techniques. J Geotech Geoenviron Eng ASCE 8(127):688–698

    Article  Google Scholar 

  28. Griffiths DV, Lane P (1999) Slope stability analysis by finite elements. Geotechnique 49(3):387–403

    Article  Google Scholar 

  29. Kellezi L, Allkja S, Hansen PB (2005). Landslide FE stability analysis. In: Proceedings international association for computer methods and advances in geomechanics, Torino, Italy, pp 545–553

  30. Bordoloi S, Yamsani SK, Garg A, Sreedeep S (2018) Critical Assessment of infiltration measurements for soils with varying fine content using a mini disk infiltrometer. J ASTM Int 47(2):868–888

    Google Scholar 

  31. Van Genuchten MT, Leij FJ, Yates SR (1991) The RETC code for quantifying the hydraulic functions of unsaturated soils. U.S. Environmental Protection Agency, Ada

    Google Scholar 

  32. Zhang LL, Zhang LM, Tang WH (2013) Modeling the unsaturated soil zone in slope stability analysis. Can Geotech J 51(12):1384–1398

    Article  Google Scholar 

  33. Zhu DY, Lee CF, Qian QH, Chen GR (2005) A concise algorithm for computing the factor of safety using the Morgenstern–Price method. Can Geotech J 42(1):272–278

    Article  Google Scholar 

  34. Bai T, Qiu T, Huang X, Li C (2014) Locating global critical slip surface using the Morgenstern-Price method and optimization technique. Int J Geomech ASCE 14(2):319–325

    Article  Google Scholar 

  35. Fredlund DG, Krahn J (1977) Comparison of slope stability methods of analysis. Can Geotech J 14(3):429–439

    Article  Google Scholar 

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Correspondence to Dooradarshi Chatterjee.

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Chatterjee, D., Murali Krishna, A. Effect of Slope Angle on the Stability of a Slope Under Rainfall Infiltration. Indian Geotech J 49, 708–717 (2019). https://doi.org/10.1007/s40098-019-00362-w

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