Abstract:

Zhang Zizhong station on metro line 5 in Beijing is a largespan embedded metro station, and is constructed with shallow tunnelling method which needs to control the settlement of free surface strictly. The ground deflection distribution control theory is used to achieve the goal of controlling the settlement of free surface. The ratios and control values of the settlement during each construction step are analyzed by the theoretical analysis, engineering analogy and numerical simulation. Based on the results of monitoring and control values during the construction, the design parameters and the support measures are presented in this paper, which can limit the settlement of free surface to less than 45mm. The methods in the design and construction that are presented in this paper are the guidance and reference to other similar constructions.

Key words: settlement of free surface  , distribution ratio  , ground deflection distribution control theory shallow tunnelling method embedded metro station