Abstract: As an important pass way underneath the inner harbor of unban Shantou area, the SuAi Pass Project processes many potential hazards induced by the tunnel construction excavated by the large diameter Tunnel Boring Machine (TBM). Based on the project construction methods and sequences, the potential risks induced by the adverse engineering and hydrological geology conditions as well as construction techniques are identified. The risk levels of the shielded tunneling segment are quantified by using the risk level evaluation and expert system methods. The sources that might result in high risks are evaluated and the method of controlling these risks are also proposed.

Key words: TBM Method, Undersea Tunnel, Construction Conditions, Construction Risks