A three-dimensional fluid-solid coupled numerical modeling of the barrier leakage below the excavation surface due to dewatering

Waterproof curtains are used as barriers to block groundwater during deep excavations; however, in practice, barrier leakage occurs frequently. This paper establishes a three-dimensional (3D) fluid-solid-coupled finite element model to analyse the effect of barrier leakage below the excavation surface. Uniform and local barrier leakages in a confined aquifer are simulated for a constant flow rate and fixed drawdown. The simulated results show that barrier leakage causes a variation in the flow direction, drawdown of the groundwater head outside of excavation, and significant additional deformation in the longitudinal direction. The factors influencing drawdown and ground settlement induced by leakage include leakage location, leakage area, barrier penetration depth, pumping-well penetration depth, and aquifer anisotropy. In addition, the simulation results show that the drawdown-time curves under various leakage conditions have similar patterns.