Numerical Analysis of an Explicit Smoothed Particle Finite Element Method on Shallow Vegetated Slope Stability with Different Root Architectures

Abstract

Planting vegetation is an environmentally friendly method for reducing landslides. Current vegetated slope analysis fails to consider the influence of different root architectures, and the accuracy and effectiveness of the numerical simulations need to be improved. In this study, an explicit smoothed particle finite element method (eSPFEM) was used to evaluate slope stability under the influence of vegetation roots. The Mohr–Coulomb constitutive model was extended by incorporating apparent root cohesion into the shear strength of the soil. The slope factors of safety (FOS) of four root architectures (uniform, triangular, parabolic, and exponential) for various planting distances, root depths, slope angles, and planting locations were calculated using the shear strength reduction technique with a kinetic energy-based criterion. The results indicated that the higher the planting density, the stronger the reinforcement effect of the roots on the slope. With increasing root depth, the FOS value first decreased and then increased. The FOS value decreased with an increase in slope angle. Planting on the entire ground surface had the best improvement effect on the slope stability, followed by planting vegetation with a uniform root architecture in the upper slope region or planting vegetation with triangular or exponential root architecture on the slope’s toe. Our findings are expected to deepen our understanding of the contributions of different root architectures to vegetated slope protection and guide the selection of vegetation species and planting locations.

Shear Strength Analysis and Slope Stability Study of Straight Root Herbaceous Root Soil Composite

“…Jia et al employed numerical analysis to reveal that the safety coefficient of slopes was substantially influenced by the plant spacing. The stability of slopes with a plant spacing of 5 m was consistent with that of bare slopes [47]. Temgoua et al observed tree spacing to improve slope stability [34,48].…”

“…The stability of shallow slopes can be enhanced by planting vegetation, amongst other methods. Slopes with plant roots on their surfaces are more stable than those with root systems at the foot or top of the slope [47]. The reinforcement effect of plant roots improves slope stability and reduces the range of influence of the sliding surface.…”

“…These results indicate that the root content and root burial depth affected slope stability, which is consistent with previous research. For example, Jia et al found that the slope safety coefficients for different root structures decreased with an increase in the slope, while Tafti et al observed that plant roots increased the safety coefficient [47,51].…”

Slope Stability Analysis Based on the Explicit Smoothed Particle Finite Element Method

“…Although the traditional finite element method (FEM), which deals with small deformation, can describe the initial failure in the surface of the structure well, it may result in large mesh distortion when dealing with large deformations after the initial failure because the aforementioned method lacks stability and accuracy and is limited in terms of solving large deformation problems in geomechanics [13,15]. The large deformation of geomaterials under time-varying loads is a difficult problem in the field of geomechanics due to considerable soil structural deformation, complex contact conditions and nonlinear soil behaviour [16]. Therefore, the development of effective numerical simulation tools will be very helpful in analysing such problems.…”

Research on the mechanism of plant root protection for soil slope stability

“…The special report by Intergovernmental Panel on Climate Change (IPCC, 2019) has urged policy makers to increase vegetation plantation in order to combat global CO 2 levels [33]. Plant slope protection engineering is an effective and aesthetically pleasing method for safeguarding slopes while also benefiting the environment and economy [34][35][36][37]. Studies have demonstrated that the survival of plants can influence soil water retention and alter the flow of water within soil [38,39].…”