Lateral spreading mitigation in gravity quay walls backfilled with coral sand through electrolysis desaturation treatment

Quay walls constructed on hydraulically filled coral sand deposits face inevitable liquefaction-induced hazards during seismic events. For mitigation, electrolysis method can be employed as an induced partial saturation technique to improve the liquefaction resistance of these coral sand foundations. This study performed two blast-induced liquefaction tests on a gravity quay wall founded on coral sand, comparing the structure's response under fully saturated conditions versus desaturated condition. The primary objectives are to investigate the seismic behavior of gravity quay walls during earthquakes and to evaluate the mechanical response of sandy soils under lateral spreading in hydraulically filled coral sand deposits. Using blast-induced liquefaction, this study examines the effects of lateral spreading on gravity quay walls, revealing that the seismic acceleration response at the base is significantly amplified. The research results indicate that when saturation is reduced by 18.8%, the liquefaction duration is reduced by 30-50%, the pore water pressure ratio is reduced by 40%, the soil liquefaction resistance is strengthened, and the damage level of the gravity quay wall is reduced from Level III to Level II. The desaturation method has a certain effect on treating lateral spread of liquefaction and reducing the degree of damage to quay walls.