An experimental study on use of biopolymer for sustainable stabilization of slopes

Strength degradation of weathered soil is a major cause of slope failures worldwide. Hence, a proper remediation technique is still a scope of research. Out of two categories of remediation technique, one category relies on external structures supporting the slope which is expensive and the other one relies on stabilizing agents which is economical. In the present study, an attempt has been made to find a solution for sustainable stabilization of soil on slopes using biopolymer. Biopolymers are edible, biocompatible and have no injectability issues. Hence, soil treated with biopolymer does not inhibit plant growth and thus, they are environment friendly, economical and socially inclusive. Two promising biopolymers, namely, Xanthan Gum which is amorphous and Gelatin which is crystalline, have been chosen for experimentation. The soil considered for this has been characterized to be silty sand. Effect of curing period as well as biopolymer concentration on improvement in strength and durability characteristics of biopolymer treated soil have been experimentally investigated. Unconfined Compressive Strength (UCS) has been chosen as a measure of strength characteristics. Weight loss, length change and volume change have been chosen as measures of durability characteristics. Results confirm the feasible application of biopolymers in sustainable slope stabilization. Test results indicate that optimum concentration of Xanthan Gum is a value between 1.5% and 2% and that of Gelatin is 1.25%. Optimum curing period has been observed to lie between 7 and 14 days. A sustainability analysis has also been performed on five combinations of biopolymer treated soil and also on base soil for a comparison.