Strength reduction method in the stability assessment of vegetated slopes

• Autorzy: Świtała, Barbara
• Języki publikacji: EN

Abstrakty

EN

The thoughtful design and mitigation of ecological slope stabilization measures rely heavily on the reliable assessment of the stability of vegetated slopes. This is a complex problem due to the many aspects of vegetation presence that must be taken into account. The numerical model should be able to consider mechanical root reinforcement and root water uptake, which can lead to soil desaturation. This paper presents the application of the strength reduction method to the Modified Cam-Clay model for unsaturated, root-reinforced soils, which allows for the quantitative estimation of slope stability. The technique is implemented in finite element software and tested using several numerical examples. Firstly, the sensitivity of the factor of safety to changes in root constitutive parameters is investigated. In the second example, the stability of the modelled slope is assessed under rainfall of a certain duration followed by progressively modifying soil strength parameters until failure occurs. Furthermore, slope stability is assessed for various durations of the rainfall period.

Słowa kluczowe

PL

metoda elementów skończonych; opady deszczu; stabilność zbocza; redukcja wytrzymałości

EN

finite element method; rainfall; root-reinforcement; slope stability; strength reduction

• Czasopismo: Architecture Civil Engineering Environment
• Rocznik: 2023
• Tom: Vol. 16, no. 2
• Strony: 151--159
• Opis fizyczny: Bibliogr. 31 poz.

Twórcy

autor

Świtała, Barbara

• PhD; Institute of Hydro-Engineering, Polish Academy of Sciences, Kościerska 7, 80-328 Gdańsk, Poland,

Bibliografia

• [1] Fellenius, W. (1936). Calculation of stability of earth dam. In Transactions. 2nd Congress Large Dams, Washington, DC, 4, 445–462.
• [2] Janbu, N. (1959). Stability analysis of slopes with dimensionless parameters. Harvard University, Division of Engineering and Applied Physics.
• [3] Morgenstern, N.R. and Price, V.E. (1965) Morgenstern, N. U., & Price, V. E. (1965). The analysis of the stability of general slip surfaces. Geotechnique, 15(1), 79–93.
• [4] Spencer, E. (1967) Spencer, E. (1967). A method of analysis of the stability of embankments assuming parallel inter-slice forces. Geotechnique, 17(1), 11–26.
• [5] Griffiths, D. V., & Fenton, G. A. (2004). Probabilistic slope stability analysis by finite elements. Journal of geotechnical and geoenvironmental engineering, 130(5), 507–518.
• [6] Cheng, Y. M., Lansivaara, T., & Wei, W. B. (2007). Two-dimensional slope stability analysis by limit equilibrium and strength reduction methods. Computers and geotechnics, 34(3), 137–150.
• [7] Griffiths, D. V., & Lu, N. (2005). Unsaturated slope stability analysis with steady infiltration or evaporation using elasto plastic finite elements. International journal for numerical and analytical methods in geomechanics, 29(3), 249–267.
• [8] Potts, D. M., & Zdravkovic, L. (2012). Accounting for partial material factors in numerical analysis. Géotechnique, 62(12), 1053–1065.
• [9] Schneider-Muntau, B., Medicus, G., & Fellin, W. (2018). Strength reduction method in Barodesy. Computers and Geotechnics, 95, 57–67.
• [10] Kolymbas, D. (2012). Barodesy: a new hypoplastic approach. International Journal for Numerical and Analytical Methods in Geomechanics, 36(9), 1220–1240.
• [11] Medicus, G., Fellin, W., & Kolymbas, D. (2012). Barodesy for clay. Géotechnique Letters, 2(4), 173–180.
• [12] Tamagnini, R. (2004). An extended Cam-clay model for unsaturated soils with hydraulic hysteresis. Géotechnique, 54(3), 223–228.
• [13] Świtała, B. M., Askarinejad, A., Wu, W., & Springman, S. M. (2018). Experimental validation of a coupled hydro-mechanical model for vegetated soil. Géotechnique, 68(5), 375–385.
• [14] Świtała, B. M., & Wu, W. (2018). Numerical modelling of rainfall-induced instability of vegetated slopes. Géotechnique, 68(6), 481–491.
• [15] Świtała, B. M., Wu, W., & Wang, S. (2019). Implementation of a coupled hydro-mechanical model for root-reinforced soils in finite element code. Computers and Geotechnics, 112, 197–203.
• [16] Świtała, B. M. (2020). Numerical simulations of triaxial tests on soil-root composites and extension to practical problem: rainfall-induced landslide. International Journal of Geomechanics, 20(11), 04020206.
• [17] Abaqus (2021). Abaqus Documentation, Dassault Systemes, Providence, RI, USA.
• [18] Roscoe, K. & Burland, J. (1968). On the generalized stress-strain behaviour of wet clay. Engineering Plasticity, 535–609.
• [19] Atkinson, J. (1993). An introduction to the mechanics of soils and foundations: through critical state soil mechanics. McGraw-Hill Book Company (UK) Ltd.
• [20] Jefferies, M. G., & Shuttle, D. A. (2002). Dilatancy in general Cambridge-type models. Géotechnique, 52(9), 625–638.
• [21] Askarinejad, A., Beck, A., Casini, F., & Springman, S. M. (2012). Unsaturated hydraulic conductivity of a silty sand with the instantaneous profile method. In Unsaturated Soils: Research and Applications (pp. 215–220). Springer, Berlin, Heidelberg.
• [22] Askarinejad, A. (2013). Failure mechanisms in unsaturated silty sand slopes triggered by rainfall (PhD thesis, ETH Zurich), Zurich, Switzerland.
• [23] Casini, F., Serri, V., & Springman, S. M. (2013). Hydromechanical behaviour of a silty sand from a steep slope triggered by artificial rainfall: from unsaturated to saturated conditions. Canadian Geotechnical Journal, 50(1), 28–40.
• [24] Van Genuchten, M. T. (1980). A closed form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Science Society of America Journal, 44(5), 892–898.
• [25] Averjanov, S. (1950). About permeability of subsurface soils in case of incomplete saturation, English Collection 7, 19–21.
• [26] Jebson, S. (2007). Fact sheet number 3: Water in the atmosphere.
• [27] Stokes, A., Douglas, G. B., Fourcaud, T., Giadrossich, F., Gillies, C., Hubble, T., ... & Walker, L. R. (2014). Ecological mitigation of hillslope instability: ten key issues facing researchers and practitioners. Plant and Soil, 377(1), 1–23.
• [28] Hubble, T. C. T., Docker, B. B., & Rutherfurd, I. D. (2010). The role of riparian trees in maintaining riverbank stability: a review of Australian experience and practice. Ecological Engineering, 36(3), 292–304.
• [29] Ji, J., Mao, Z., Qu, W., & Zhang, Z. (2020). Energy-based fibre bundle model algorithms to predict soil reinforcement by roots. Plant and Soil, 446(1), 307–329.
• [30] Murgia, I., Giadrossich, F., Mao, Z., Cohen, D., Capra, G. F., & Schwarz, M. (2022). Modeling shallow landslides and root reinforcement: A review. Ecological Engineering, 181, 106671.
• [31] Świtała, B. M. (2016), Analysis of Slope Stabilisation by Soil Bioengineering Methods (PhD thesis, University of Natural Resources and Life Sciences), Vienna, Austria.

Identyfikatory

DOI

10.2478/acee-2023-0024