Hydrological Modification of Laterite Soil Considering Root Soil Interaction

Slope bioengineering has been practiced worldwide as an environmental friendly way of stabilizing shallow slopes. The contribution of the two plant aspects, namely hydrological and mechanical effects in slope stabilization, can be understood by analyzing root soil interaction. Plant roots act as a structural element to provide mechanical reinforcement. With the growth of roots day by day, transpiration becomes significant, which induces soil suction. The induced suction is the governing factor that determines the suitability of roots in stabilizing a soil slope terrain. Despite vetiver grass (Crysopogon zizanioides) being one of the most widely used grasses in geotechnical and geo-environmental engineering applications, the study of its root effects on soil water retention curves (SWRC) and permeability of soil is very rare. The purpose of the present study is to experimentally investigate the effect of vetiver grass on hydrological properties of laterite soil like suction, porosity and permeability which varies with root content and age of vegetation. The vetiver plants showed significant effect in improving the hydrological properties of laterite soil which implies its suitability to be used as a method to prevent slope instability due to rainfall in shallow slopes.