Abstract: This paper provides a case study on the braced excavation for the air shaft between Xinzhuang Station and Municipal Government Station of Nangjing Metro Line 3.  Inverse construction was proposed for the excavation.  Numerical analysis was performed to obtain the stresses within the support system under the most critical load combination during construction and after the air shaft is in service.  The design of the reinforcement in the diaphragm wall, ring box beam, stringers and bottom slab was performed based on the results of the numerical analysis.

Key words: Braced Excavation, Nanjing Metro, Inversed Construction, diaphragm wall, construction process