“Reporting on the latest advancements in geotechnical engineering, this paper delves into the stability of deep foundation pits in water-rich sandy strata, a critical aspect of underground construction safety. The research, grounded in the analysis of subway station launch shaft pit leakage incidents, reveals that partial leakage significantly amplifies retaining wall displacement and ground settlement, with the maximum values post-leakage being 1.29 to 1.47 times and 1.16 to 2.67 times the pre-leakage measurements, respectively. The study underscores the "jump" fluctuation in groundwater level as a key indicator of impending leakage disasters and proposes a combined grouting and high-pressure jet spouting pile treatment as an effective solution for managing leakage in such strata.”