Pull-Out Strength of Root

摘要

The influence of vegetation covering on the slope has come into more and more notice in recent years. It is easy to understand that the plants can upscale the soil cohesion around the surface, achieving the goal of increasing the slope stability. Moreover, instead of construction methods (i.e. soil nails) to stablish the slope, green vegetation has undeniable aesthetics advantage which could satisfy residents' demand on more beautiful living environment. Thus, planting greening on slope has been recommended lately. Most studies show that the pull-out strength of root relies on a variety of factors, such as root geometry (diameter, length, and branching characteristics), mechanics properties (Young's modulus and Poisson's ratio) and soil-root interaction (soil type, confining pressure and friction coefficient). In this study, the 2D models using Finite Element Method (FEM) were applied to determine the pull-out strength of individual roots with different factors mentioned above. The results show that with a relative higher length or diameter value, the peak pull-out strength would also be higher as the contact area between soil and root increased. Additionally, the straight-shape root exhibits higher pull-out strength than cone-shape root, also due to the difference of contact area. In conclusion, some simple 2-D Finite Element models was developed to get better understanding during root pulling-out process and the results shows the geometry could affect and modify the pull-out strength of roots significantly.