Experimental–Numerical Assessment of the Geomechanical Potential of Chrysopogon zizanioides (L.) Roberty for Root Reinforcement of Filtered Mine Tailings Under Controlled Conditions

Mine tailings are highly disturbed technogenic materials whose low mechanical stability may limit mine closure and long-term land rehabilitation. This study evaluates the geomechanical potential of Chrysopogon zizanioides (L.) Roberty, commonly known as vetiver grass, to improve the shear-strength response of filtered mine tailings under controlled laboratory and numerical modelling conditions. The study does not constitute field-scale validation of phytostabilization; rather, it examines the contribution of vetiver roots to apparent cohesion and shallow slope stability. A combined experimental–numerical framework was implemented, including laboratory characterization of unreinforced and root-reinforced tailings, derivation of Mohr–Coulomb shear-strength parameters, and limit-equilibrium slope-stability analysis under predefined root-growth and root-orientation scenarios. The results indicate that vetiver roots increased apparent cohesion by up to 34.6%, whereas changes in friction angle remained below 10%, suggesting that the dominant reinforcement mechanism is pseudo-cohesive rather than frictional. The calculated factors of safety varied according to slope geometry, assumed root length, root orientation, and simplified water-condition scenarios. However, the findings remain limited to controlled experimental and numerical conditions. Field-scale validation, long-term root monitoring, moisture variability, nutrient availability, phytotoxicity, contaminant immobilization, and life-cycle performance should be assessed before practical implementation. This study provides preliminary geomechanical evidence of vetiver-induced root reinforcement in filtered mine tailings.