Inducing partial saturation within the soil matrix has emerged as an effective approach to enhancing liquefaction resistance in fully saturated sands. Conventional methods for mitigating liquefaction susceptibility often involve substantial costs, complex implementation procedures, and potential environmental implications. This study investigates the enhancement of cyclic liquefaction resistance in sandy soils through induced partial saturation by air injection. Undrained cyclic triaxial tests under stress control were carried out on specimens in fully saturated, air-injected, and partially saturated states, considering a range of relative densities and loading configurations. The effect of air injection pressure and desaturation on the cyclic response was systematically examined. Liquefaction resistance curves and safety factors against liquefaction were evaluated for different earthquake records. Furthermore, a comparative analysis of the dynamic characteristics of fully saturated and partially saturated sand specimens was conducted to investigate the effect of saturation levels on their cyclic response. The experimental results validated the increased liquefaction resistance achieved through the induction of partial saturation. Moreover, the results demonstrated a notable decline in generated excess pore water pressure corresponding to a reduction in the degree of saturation to 95%. The liquefaction resistance ratio (CRR) increased significantly with a saturation level of 75%, irrespective of relative density. Furthermore, the target degree of saturation ( Sr target ) was determined for loose to medium-dense relative density.
Das et al. (2026) studied this question.