在广泛分析目前深基坑降水的设计计算理论和施工的基础上，建立了三维渗流的有限元模型，编制了三维有限元计算程序，并以武汉长江隧道武昌盾构井深基坑降水工程为例进行计算。通过将有无悬挂式帷幕两种工况的水头降深计算结果与实际存在悬挂式止水帷幕的实际监测值进行对比，定量说明悬挂式止水帷幕对基坑降水的影响。

Based on an extensive analysis on the design theory and construction of the dewatering of deep foundation pits, the paper establishes a 3dimensional finite element seepage model, accomplishes a 3dimensional finite element program and taking the dewatering of the Wuchang shield launching shaft of Wuhan Yangtse River Crossing Tunnel project as an example, makes relevant calculations. By comparing the calculation results of the water level lowering with/without pensile curtains with the measured data of the water level lowering with pensile curtains, the paper illustrates the effects of the pensile curtains on the dewatering of foundation pits.