Based on the shield boring of the exit section of Shiziyang tunnel on Guangzhou-Shenzhen-Hongkong passenger-dedicated railway,the authors present the selection and optimization of the boring parameters,the control measures,boring process,difficulties and the countermeasures of the large-diameter slurry shield in water-rich soft ground with shallow cover.

Overlapping tunnels will influence each other during construction stage,and will result in a series of problems such as ground subsidence controlling,particularly for watery and weak surrounding rocks in shallow depth.

The Changling Tunnel goes through the Kuqiaoxi sector with shallow burial depth and abundant groundwater.