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Physical and Numerical Modeling of Clayey Slopes Reinforced with Roots


The purpose of this study was to explore the influence of vegetation on the stability of clayey slopes. Physical models with varying layer depths reinforced with roots were performed in a geotechnical centrifuge. The soil reinforced with vegetation was simulated with a mixture of clay and fiberglass which present similar shear strength properties. Displacement vectors of the physical models are obtained using the Particle Image Velocimetry (PIV). The computed resultant displacements showed that the slip surface varied with respect the root depth. Additionally, numerical models of the tests in centrifuge were made using finite elements and Bishop's method. The results obtained also show that the deeper the roots, the deeper the sliding surface. The slip surface moves from a depth of the slope toe (slope without reinforcement) to a depth close to twice the height of the slope. Regarding the factor of safety, it varies from a value of 0.7 for slopes without vegetation to 1.19 for a root depth of three meters. Moreover, the factor of safety increases as root depth increases.

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  1. Fan C-C, Su C-F (2008) Role of roots in the shear strength of root-reinforced soils with high moisture content. Ecol Eng 33:157–166.

    Article  Google Scholar 

  2. Mickovski SB, Van Beek LPH (2009) Root morphology and effects on soil reinforcement and slope stability of young vetiver (Vetiveria zizanioides) plants grown in semi-arid climate. Plant Soil 324:43–56.

    Article  Google Scholar 

  3. Nawagamuwa UP, Sarangan S, Janagan B, Neerajapriya S (2014) Study on the effect of plant roots for stability of slopes. In: Landslide Science for a Safer Geoenvironment. Springer International Publishing, Cham, pp 153–158.

  4. Chenari RJ, Pishkhani SS, Fard MK, Sosahab JS (2018) Experimental and numerical investigation of dynamic properties of soil stabilized by young Vetiver. Ital Geotech J 52(1):49–58.

  5. Foresta V, Capobianco V, Cascini L (2020) Influence of grass roots on shear strength of pyroclastic soils. Can Geotech J 57:1320–1334.

    Article  Google Scholar 

  6. Toulegilan MM, Chenari RJ, Neshaei MAL, Forghani A (2020) Changes in stability conditions of clay slopes due to leaching: a case study. SN Appl Sci 2(6):1–10.

    Article  Google Scholar 

  7. Fan C-C, Lai Y-F (2014) Influence of the spatial layout of vegetation on the stability of slopes. Plant Soil 377:83–95.

    Article  Google Scholar 

  8. Liang T, Bengough AG, Knappett JA, MuirWood D, Loades KW, Hallett PD, Boldrin D, Leung AK, Meijer GJ (2017) Scaling of the reinforcement of soil slopes by living plants in a geotechnical centrifuge. Ecol Eng 109:207–227.

    Article  Google Scholar 

  9. Chiatante D, Scippa SG, Di Iorio A, Sarnataro M (2002) The influence of steep slopes on root system development. J Plant Growth Regul 21:247–260.

    Article  Google Scholar 

  10. Burylo M, Hudek C, Rey F (2011) Soil reinforcement by the roots of six dominant species on eroded mountainous marly slopes (Southern Alps, France). CATENA 84:70–78.

    Article  Google Scholar 

  11. Ghestem M, Cao K, Ma W, Rowe N, Leclerc R, Gadenne C, Stokes A (2014) A framework for identifying plant species to be used as ecological engineers for fixing soil on unstable slopes. PLoS ONE 9:8.

    Article  Google Scholar 

  12. Garnier J, Gaudin C, Springman SM, Culligan PJ, Goodings D, Konig D, Kutter B, Phillips R, Randolph MF, Thorel L (2007) Catalogue of scaling laws and similitude questions in geotechnical centrifuge modelling. Int J Phys Model Geotech 7(3):1–23.

    Article  Google Scholar 

  13. Tl C, Zhou C, Gl W, El L, Dai F (2017) Centrifuge model test on unsaturated expansive soil slopes with cyclic wetting–drying and inundation at the slope toe. Int J Civ Eng 16:1341–1360.

    Article  Google Scholar 

  14. Yaghoobzadeh S, Azizkandi AS, Salehzadeh H, Hasanaklou SH (2021) Effect of EPS beads on the behavior of sand–EPS and slope stability using triaxial and centrifuge tests. Int J Civ Eng 19:1269–1282.

    Article  Google Scholar 

  15. Sonnenberg R, Davies MC, Bransby MF, Hallett PD, Bengough AG, Mickovski SB, Hudacsek P (2007) Centrifuge modelling of slope reinforcement by vegetation. In: Proceedings of the 14th European conference on soil mechanics and geotechnical engineering, Madrid. 3. 1551–1556.

  16. Sonnenberg R, Bransby MF, Hallett PD, Bengough AG, Mickovski SB, Davies MC (2010) Centrifuge modelling of soil slopes reinforced with vegetation. Can Geotech J 47:1415–1430.

    Article  Google Scholar 

  17. Sonnenberg R, Bransby MF, Bengough AG, Hallett PD, Davies MCR (2012) Centrifuge modelling of soil slopes containing model plant roots. Can Geotech J 49:1–17.

    Article  Google Scholar 

  18. Eab KH, Likitlersuang S, Takahashi A (2015) Laboratory and modelling investigation of root-reinforced system for slope stabilisation. Soils Found 55:1270–1281.

    Article  Google Scholar 

  19. Liang T, Knappett JA (2015) Centrifuge modelling of vegetated slopes under earthquake loading. In: 6ICEGE-6th International Conference On Earthquake Geotechnical Engineering, Christchurch, New Zealand. Christchurch, New Zealand

  20. Liang T, Knappett JA, Bengough AG, Ke YX (2017) Small-scale modelling of plant root systems using 3D printing, with applications to investigate the role of vegetation on earthquake-induced landslides. Landslides 14:1747–1765.

    Article  Google Scholar 

  21. Chok YH, Kaggwa WS, Jaksa MB, Griffiths DV (2004) Modelling the effects of vegetation on stability of slopes. In: Proceedings of the 9th Australia New Zealand Conference on Geomechanics. Centre for Continuing Education, Uni Auckland, Auckland, New Zealand, pp 391–397

  22. Gentile F, Elia G, Elia R (2010) Analysis of the stability of slopes reinforced by roots. In: WIT Transactions on Ecology and the Environment. WIT Press, pp 189–200.

  23. Stanier SA, Blaber J, Take WA, White DJ (2016) Improved image-based deformation measurement for geotechnical applications. Can Geotech J 53:727–739.

    Article  Google Scholar 

  24. White DJ, Take WA (2002) GeoPIV: Particle Image Velocimetry (PIV) software for use in geotechnical testing

  25. Carvajal D (2021) Physical modeling of the effect of suction on slope stability in fine soil (In spanish). Dissertation, Escuela Colombiana de Ingeniería Julio Garavito

  26. Rocha Y (2021) Physical modeling in centrifuge of the effect of root type on slope stability (In spanish). Dissertation, Escuela Colombiana de Ingeniería Julio Garavito.

  27. Noorasyikin MN, Zainab M (2016) A Tensile strength of bermuda grass and vetiver grass in terms of root reinforcement ability toward soil slope stabilization. IOP Conf Ser Mater Sci Eng.

    Article  Google Scholar 

  28. Aggarwal P, Choudhary KK, Singh AK, Chakraborty D (2006) Variation in soil strength and rooting characteristics of wheat in relation to soil management. Geoderma 136:353–363.

    Article  Google Scholar 

  29. Divya PV, Viswanadham BVS, Gourc JP (2017) Centrifuge model study on the performance of fiber reinforced clay-based landfill covers subjected to flexural distress. Appl Clay Sci 142:173–184.

    Article  Google Scholar 

  30. Moreno-Espíndola IP, Rivera-Becerril F, de Jesús Ferrara-Guerrero M, De León-González F (2007) Role of root-hairs and hyphae in adhesion of sand particles. Soil Biol Biochem 39(10):2520–2526.

  31. Cohen D, Schwarz M, Or D (2011) An analytical fiber bundle model for pullout mechanics of root bundles. J Geophys Res 116(F3).

  32. Schwarz M, Cohen D, Or D (2011) Pullout tests of root analogs and natural root bundles in soil: Experiments and modeling. J Geophys Res 116(F2).

  33. Soric Z, Galic J, Rukavina T (2008) Determination of tensile strength of glass fiber straps. Mater Struct Constr 41:879–890.

    Article  Google Scholar 

  34. Wu Z, Leung AK, Boldrin D, Ganesan SP (2021) Variability in root biomechanics of Chrysopogon zizanioides for soil eco-engineering solutions. Sci Total Environ 776:145943.

    Article  Google Scholar 

  35. Wu TH (1995) Slope stabilization. In: Morgan RPC, Rickson RJ (eds) Slope Stabilization and Erosion Control. E & FN Spon, London, pp 221–264

    Google Scholar 

  36. Gray DH, Sotir RB (1996) Biotechnical and soil bioengineering slope stabilization: a practical guide for erosion control. Wiley, USA

  37. Wu TH, McKinnell WP III, Swantson DN (1979) Strength of tree roots and landslides on Prince of Wales Island, Alaska. Can Geotech J 16:19–33

    Article  Google Scholar 

  38. Desai CS, Siriwardane HJ (1984) Constitutive laws for engineering materials with emphasis on geologic materials, 1st edn. Prentice-Hall, Englewood Cliffs, NJ

    MATH  Google Scholar 

  39. Dyson AP, Tolooiyan A (2018) Optimisation of strength reduction finite element method codes for slope stability analysis. Innov Infrastruct Solut 3:38

    Article  Google Scholar 

  40. Griffiths DV, Lane PA (1999) Slope stability analysis by finite elements. Géotechnique 49(3):387–403

    Article  Google Scholar 

  41. Johnson K, Lemcke P, Karunasena W, Sivakugan N (2006) Modelling the load–deformation response of deep foundations under oblique loading. Environ Model Softw 21:1375–1380.

    Article  Google Scholar 

  42. Gasparre A (2005) Advanced laboratory characterisation of London clay. Ph.D. thesis, Imperial College, London

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

    Article  Google Scholar 

  44. Aziz S, Islam MS (2022) Mechanical effect of vetiver grass root for stabilization of natural and terraced hill slope. Geotech Geol Eng.

    Article  Google Scholar 

  45. Augarde CE, Lee SJ, Loukidis D (2021) Numerical modelling of large deformation problems in geotechnical engineering: A state-of-the-art review. Soils Found 61(6):1718–1735

    Article  Google Scholar 

  46. Soga K, Alonso E, Yerro A, Kumar K, Bandara S (2016) Trends in large-deformation analysis of landslide mass movements with particular emphasis on the material point method. Géotechnique 66(3):248–273

    Article  Google Scholar 

  47. Chok YH, Jaksa MB, Kaggwa WS, Griffiths DV (2015) Assessing the influence of root reinforcement on slope stability by finite elements. Int J Geo-Eng 6(1):1–13.

    Article  Google Scholar 

  48. Tsige D, Senadheera S, Talema A (2020) Stability analysis of plant-root-reinforced shallow slopes along mountainous road corridors based on numerical modeling. Geosciences 10(1):19.

    Article  Google Scholar 

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The authors would like to acknowledge the Escuela Colombiana de Ingeniería Julio Garavito for funding this research with the internal project for young researchers, “Study of the effect of roots of the grass in soil reinforcement.”


From Escuela Colombiana de Ingeniería Julio Garavito with the internal project for young researchers, “Study of the effect of roots of the grass in soil reinforcement.”

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Correspondence to Cristhian Mendoza.

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Lozada, C., Mendoza, C. & Amortegui, J.V. Physical and Numerical Modeling of Clayey Slopes Reinforced with Roots. Int J Civ Eng (2022).

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  • Roots reinforcement
  • Clayey soil
  • Slope stability
  • Geotechnical centrifuge