An equation for predicting shear strength envelope with respect to matric suction

Abstract Determining the shear strength parameters of unsaturated soils generally involves costly, time-consuming and sophisticated testing programme. This paper proposes a new method for prediction of shear strength with respect to matric suction. The variation of shear strength with respect to matric suction is described by using the air-entry value and the internal friction angle of a soil specimen. The validity of the method is tested for a number of suction strength data available in the literature. The shear strengths with respect to matric suction obtained from the proposed method are in nicely good agreement with experimental results.