Effect of degree of saturation on the shear strength properties of soils containing herbaceous plant root systems

Abstract

In this study, in order to clarify the effect of rainwater infiltration on the reinforcing effect of vegetation works, specimens were prepared by sowing seeds of non-native herbaceous plants (KBG) in sandy and clay soil specimens to grow and develop root systems, after which the specimens were subjected to constant pressure direct shear tests under different flooding conditions. The saturation of the specimens was adjusted between three levels by flooding and dewatering. The maximum shear stress was found to decrease as the specimens approached the saturated state, regardless of the soil type. However, the root system in the specimen was confirmed to improve the toughness of the soil even at high saturation, and it is likely that the reinforcing effect of the root system is not lost by rainwater infiltration.