Shed-pipe Design and Construction of Xiang'an Sub-sea Tunnel Portal in Xiamen

The design parameters of shed-pipes of Xiamen Xiang'an sub-sea tunnel portal are presented and then the impacts and effects of shed-pipes are analyzed by FLAC (Fast Lagrangian Analysis of Continua). The key technologies of shed-pipe construction are summarized,and the problems and solutions in the con- struction process are mentioned.The 40 m long shed-pipes combined with grouting can act as“carrying arch”,which makes the distributing of ground subsidence uniform and can control the maximum settlement effectively.The problems of stratum disturbance,which caused by cyclic medium of boreholes,are overcome. The shed-pipes play important roles in tunneling in terms of safety.