Effect of stress state and particle-size distribution on the stress reduction of sandy soils during saturation

In this study, stress reduction due to saturation of sandy soils is investigated via conventional triaxial shear strength apparatus. Triaxial tests were performed on dry samples, saturated samples and initially dry samples followed by saturation during shearing. Effects of stress states, initial loading and unloading and particle-size distribution (PSD) curve were studied on the behaviour of the samples. It was observed that the amount of stress reduction increases by the decrease in the relative density and the increase in the confining pressure and the shear stress level during saturation. With the same uniformity coefficient, the coefficient of stress recovery increases as the maximum particle size increases, results in less collapse in sandy soils.