Evaluation of slope stabilization by vegetation reinforcement: modelling aspects

Abstract

Abstract
The slope stability is one of the main concerns in geotechnical engineering. The focus of this study is the numerical assessment of the reinforcement using planting (vegetation) as an environmentally- friendly technique to increase the safety factor of slopes against failure. For this purpose, the physical interaction of the vegetation root with the soil structure, known as apparent root cohesion, is introduced in the Mohr-Coulomb failure model. Therefore, and using parametric study, the effects of root cohesion (Cr) and root depth (Zr) corresponding to different types of plants/trees on safety of different slopes are analyzed using both Numerical and Limit Equilibrium methods. The considered Cr and Zr values are (0,5,10,15,20 and 25 kPa) and (0,0.5,1.0,1.5 and 2.0 m) respectively, which are examined in various cases of slopes with slope angles (β°) of 18.4°,26.6°,33.7°,39.8°,45° and 55°. Also, the effects of the areas of the slope that possibly can be covered by vegetation are simulated in different scenarios and the results are compared with no root reinforcement approach. The results show that the stability of the slope increased by increasing both the root cohesion and the depth. This increase is significant even in cases with the steep slopes. In terms of the area covered by vegetation, the results found that the scenarios that the vegetation is incorporated on slope surface possess a larger factor of safety than crest and toe covered zones. In addition, no influence is observed from the toe region vegetation cover.