ABSTRACT
In Bishop’s equation for the effective stress, the contribution of suction to the effective stress is controlled through a parameter, χ, which is the so-called effective stress parameter. Unsaturated soils show complex hydro-mechanical behavior and the interaction of different phases controlling the behavior of unsaturated soils is a great concern in the determination of the effective stress parameter. This parameter is also affected by other factors such as stress history, soil placement, and soilwater hysteresis. Therefore, analytical determination of the effective stress parameter is a difficult task. In the present study, a pore network model is developed to predict the variation of the effective stress parameter at different saturation and suction levels. In the proposed method, the pore size distribution of the soil is estimated from Soil Water Retention Curve (SWRC) and the effective stress parameter, χ, is determined directly from pore network simulation. Moreover, model simulations are employed to shed light into the soil-water hysteresis phenomena and its subsequent effects on the effective stress parameter.
