The creep property of artificial frozen soil curtain wall is obvious. In the calculating model which is based on the tunnel crossing the bottom plate of using station in Shanghai subway

it is considered that the frozen soil curtain wall is made up of creep media

both soil in tunnel and upper structure are elastic materials

outside soil of the frozen soil curtain wall and structure of station are soil spring. Analysis of time-space effect on excavation and support in frozen soil curtain wall of tunnel is made by 3D FEM- MARC. The calculation results are in good agreement with the test values; so it shows that it is reasonable and creditable to analyze the time-space effects of frozen soil curtain wall by 3D FEM. Moreover

the stabilities of the bottom plate of station

frozen soil curtain wall and the structure of support are increased by decreasing the exposed time of the frozen soil curtain wall and applying the way of step-by-step excavation.