Abstract: The deep excavation activities in the metro protective zone demand a safe excavation support design and construction in order to maintain the safe operation of the metro system. This paper presents a case history of the deep excavation in the metro protective zone in Shenzhen. The potential main and difficult aspects of the construction of supporting system and their mitigation measures are evaluated in the paper. The proposed supporting system is recommended and the selection process are also discussed. Numerical analyses on the construction progress using the selected supporting system are performed. The results indicate that the deformation at both the entrance and exit of the tunnel are met the requirements.

Key words: Metro Protective Zone, Deep Excavation, Supporting System Design, Numerical Analysis