Abstract：The settlement of a subway station undercut with shallow overburden has important effect on the construction safety. The engineering field of Suzhou Street Station of Beijing No.10 Subway has complex strata with different mechanical characters. According to the three-dimensional spatial distribution of strata，a three-dimensional geological model of the subway station has been built. The physico-mechanical parameters of every stratum have been ascertained by test. On the basis of the subway engineering，the course of the cave-pile method is abstracted to six construction step. The equivalent simulation method is used to abstract the preceding reinforcing stratum. The FLAC3D is used to simulate the construction process. The caving project is optimized by simulation. The deformations of the soil around the station and ground settlement in every construction step have been analysed. The construction step that causes the largest ground settlement has been found by three- dimensional numerical simulation. Through the comparison between the deformation monitoring data of pilot drift cavity with calculation results，the reliability of the calculation results has been testified. At the same time，the eventual ground settlement is forecasted by the calculation results.
