Biostabilization of Mandaman dump slope, lndia

An integrated study of the biological stabilization of a coal-mine overburden dump slope has been carried out at Mandaman, 35 km from Dhanbad in eastern India. Native grasses-bamboo (Dendrocalmus strictus) and kashi (Saccharum spontaneum)-are important species that can stabilize the dump slopes. The grasses have good soil binding capacity and help to control soil erosion and improve dump stability. Field observation of their growth performance has indicated that the mean grass height and root depth are 232 (±74) cm and 46 (±5) cm, respectively, after three years and the below-ground root biomass is 474 (±69) g m -2 . The mechanical and hydrogeological actions of the grass roots have improved the shear strength properties of the dump material. Numerical modelling has shown that the roots of these grasses increase the factor of safety of the dump slope from 1.2 to 1.4 and thus play a substantial role in the maintenance of long-term stability.