Abstract: In this paper, a case study of the seepage influence analysis is presented considering different cut-off wall depths at a subway deep excavation project in Shenzhen. The two dimensional numerical analysis results indicate that, the groundwater drawdown outside the excavation area depends on the permeability coefficient of the soil layers at the toe of the cut-off wall. The loss of groundwater could be minimized when the tow of the cut-off wall is penetrated into the impervious layers. Further assessment of the potential ground subsidence induced by the groundwater extraction could be referred as the early prediction and judgement for the deep excavation risk control.

Key words: Subway Excavation, CutOff Wall, Seepage, SEEP/W, Ground Subsidence