Effects of the Root's Distribution on the Stability of Slope

Vegetation has been recognized to play a major role in the reinforcement of slopes against shallow landslides. The intensity of root reinforcement mainly depends on roots distribution and root tensile strength. The aim of this study is to determine the effects of morphological characteristics of vetiver roots system on slope stability. A series of experiments were carried out to obtain the physical and mechanical parameters of soil with vetiver roots. A preliminary analysis is performed to assess the impact of root morphologies on the slope's safety factor. The results indicate that the roots have significant influence on the shear strength parameters of slope soil. The increasement of cohesive force is more obvious than that of the intrinsic friction angle. Hence, combined the experiments and theory, the formula is deduced to calculate the safety factor of the slope considering the distribution angle of root system. Furthermore, when the angle between root system and shear surface reaches 156 & DEG;, the root system works relatively better in reinforcement. It demonstrates that root orientations significantly affect the shear resistance provided by root-permeated soil. Finally, the implementation of soil-root reinforcement models was allowed to calculate the safety factors of shallow slope and evaluate the vegetation contribution to soil stability.