Experimental study and constitutive modeling of volume change behavior in unsaturated soils

Abstract

Unsaturated soils often show complex coupled hydro-mechanical behavior. We present a simple way to explore the 1D compression mechanical behavior of unsaturated soils under a constant degree of saturation by controlling the sample void ratio and suction. The experimental results presented here verify that the proposed method can control the degree of saturation during compression. The experimental data show that the hardening factor exhibits a linear relationship with the logarithmic degree of saturation. We apply a volume change equation using the hardening factor and effective stress as basic variables to simulate the hydro-mechanical behavior of unsaturated soils. We conducted numerical simulations to assess the model performance. Comparisons between the experimental data and simulations indicate that the model can well reproduce the mechanical and hydraulic response of unsaturated soils.