This paper describes time dependency of the constant volume shear strength of clayey soils.
Considerable difference between the experimental constant volume shear strength and theoretical value derived from the Sekiguchi-Ohta model is found out. It is thought that the difference is caused by time dependency of shear strength, which is experimentally quantified in this paper. Then, the constant volume shear strength is corrected by applying a correction factor, and reasonable agreement is achieved between theoretical shear strength and corrected experimental data.