Stability analysis of slope reinforced by roots network

Many studies concerning about stability analysis of slope have been carried out. Most works of stability analysis were based on effects of strength parameters and the shape of slope. The trees at slope also affect to slope stability. Therefore, it is necessary to clarify the mechanism of slope failure which reinforced by roots network. But the effect of roots network depends on various conditions. Now, all relationships between the tensile strength of roots and the shearing strength of soil involving roots network are not clarified. The authors have tried three types of shear tests, direct shear test, triaxial compression test and field direct shear test under various conditions. The apparent cohesion c increase with the amount of roots. The stability analysis method on a slope formed from soil having roots network is proposed. The mechanism on the effects of roots network were investigated using Fellenius method and generalized limit equilibrium method. The experimental results obtained from model tests agree with the analytical ones. The stability analyses were carried out for the one site in which slope failure had occurred. It was confirmed that the presence of roots significantly influence to the slope stability.