Plant root reinforcement against local failure mechanism in protecting slope

Effectiveness of plant root reinforcement in protecting shallow landslides was investigated with a method of slope stability analysis. In the study, plant roots contributed effectively to increase the local safety factors of slope and subsequently increased the over-all safety factor to stabilize the slope. The natural plant roots increased the local safety factor by providing additional shear strength locally to the shear plane of the investigated slopes. Study showed that the strength of soil at certain location along the shear plane drastically reduced to a residual level and the local failure was imminent for slopes without root reinforcement. On the other hand, the roots significantly contributed additional strength to increase such local residual strength of slope soil and hence increased the safety factor for same slopes with root reinforcements. The shear strengths of roots were determined with root diameters, number of roots and tensile strength of roots. The root shear strengths were incorporated as reinforcements into the slope stability analysis method. The used method for slope stability analysis calculated the local as well as over-all factor of safety with root reinforcement. Existing published data regarding the roots were used in the analyses. A number of analyses for safety factor calculations were done with different root reinforcement situation in the slopes. Parametric studies among different root parameters with safety factor and shear strength were also studied.