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Land subsidence caused by excessive groundwater withdrawal has become a global hazard, which demands further researches and the potential measures to control. Using the FlowTrac Ⅱ consolidation test system, six compression tests were designed to investigate the stress state and stress paths of sand within confined aquifers under conditions of withdrawal and recharging. The deformation characteristics of aquifer sand were studied under different withdrawal-recharging patterns. During pumping and recharge processes, sand deformation responses were observed to lag behind changes in applied stress. The characteristics of this hysteresis effect on deformation were summarized. The alternating phenomenon of rebound and compression of sand deformation under the recharging process is analyzed. When the recharging effect was relatively small than withdrawing effect under the stable withdrawal-recharging pattern, the compression deformation was observed in the recharging process. The research results provide a rational explanation for the continuous compression deformation of the aquifer during groundwater level recovery and offer experimental evidence for the rational design of artificial groundwater recharge in engineering construction.

In deep excavation engineering, the implementation of cut-off walls stands as a crucial measure to ensure structural support stability. However, the existing theories for dewatering design often overlook the variations in cut-off wall penetration depths, potentially compromising the efficacy of groundwater control strategies. Addressing this gap, this study conducts a comprehensive investigation into the dynamics of groundwater levels within confined aquifers during the dewatering process of strip excavation pits with cut-off walls. Central to this inquiry is the conceptualization of the entire excavation pit as a singular large-diameter well, with the open part beneath the cut-off wall in the confined aquifer serving as a constant-flux boundary. Employing an advanced analytical modeling approach, the study formulates a robust framework to describe the intricate interplay of unsteady groundwater flow phenomena. Leveraging the techniques of the Laplace and finite cosine transform methods, a semi-analytical solution is derived to elucidate groundwater drawdown patterns over time. The validation of the proposed solution against finite element method results underscores its fidelity and applicability. The parametric analysis reveals a dynamic evolution in drawdown characteristics within the confined aquifer, transitioning from initially cone-shaped distributions to more linear profiles that eventually stabilize with prolonged dewatering. This evolution is governed by the aquifer’s inherent anisotropy and the barrier effect exerted by the depth of cut-off wall penetration. The parametric research also underscores the critical role of lateral boundary distance in influencing groundwater drawdown patterns. The presented solutions can be used to identify optimal penetration depth ratios tailored to specific parameters, thereby offering insights for optimizing dewatering strategies for deep excavation groundwater control. Moreover, a case study was included in this study using the proposed analytical solution, and a comparison was made with field data to validate the practical applicability of the approach.