Effect of Pre-Existing Underground Structures on Groundwater Flow and Strata Movement Induced by Dewatering and Excavation

Based on an actual excavation of a metro station in Tianjin, China, fluid–solid coupling numerical model was developed to study the characteristics groundwater flow and strata movement induced by dewatering considering barrier effect pre-existing adjacent underground structures. Two parameters were selected for model: distance between existing structure (D), buried depth (H). By comparing distribution drawdown deformation modes retaining under different working conditions, influence mechanism structures revealed. The results show that pile foundations have effects deformation. Generally, maximum could be enlarged structure, while deflection would reduced ground settlement either or reduced. Additionally, as D decreases H increases, much greater smaller appear, which together affect behavior. On one hand, lead soil consolidation, other settlement. Thus, complex development specific analysis should performed assess this practice, based D.