Numerical study on effect of enclosed air in void water on liquefaction of unsaturated soil

Abstract

In this study, the effect of the enclosed air contained in unsaturated soil on the cyclic shear was investigated numerically. First, the governing equation of unsaturated cyclic triaxial test was developed based on the mass balance equations and constitutive equations with consideration of the enclosed air. Then, the series of numerical simulations were performed to clarify the effect of the change of mass between enclosed air and continue air, and the existence of enclosed air before starting cyclic loading. The simulated results showed that the consideration of the enclosed air affected the behavior of the suction, the pore water and the air. Finally, the simulations aimed to the unsaturated cyclic triaxial test showed the good agreement with the experiment in the point of view of reproducing the tendency of decrease of the suction.