Abstract: The daily running of metro tunnel under complex environment during the excavation of upper foundation pit should be guaranteed. Accordingly, the threedimensional numerical simulation calculation and construction monitoring data analysis methods are adopted for a municipal utility tunnel above a metro tunnel section in Zhengzhou. Conclusions are drawn as follows. (1) By selecting a rational foundation pit retaining plan, the disturbance on metro tunnel induced by foundation pit retaining structure construction can be reduced. (2) For areas with good engineering geology, by refining the excavation method of the upper foundation pit and adopting the plan of base reinforcement + drawing construction, the normal operation of the metro tunnel can be guaranteed.

Key words: complex environment, shield tunnel, metro, upper foundation pit, excavation unloading