Abstract: At present, the construction conditions of the urban metro are complex, and some stations do not have enough reserved conditions such as lifting holes and enough clear space for shield receiving and transition. As a result, a kind of disassembled shield is proposed for passing the station in confined space by taking Ningbo Railway Station on Metro Line No. 4 for example. In the design and manufacturing stage, the cutterhead, front shield, middle shield and shield tail of the machine are divided into modules to control the mass and size, which are connected by flanges and bolts. During the construction stage, the disassembly and assembly of shield is divided into 8 standard steps to successfully pass through station in confined space. By adopting the method mentioned above, the damage on shield induced by disassembly in confined space can be effectively avoided, the shield stability after reassembly can be guaranteed, and the shield disassembly efficiency and safety can be improved. The secondary launching and advancing of shield have been successfully achieved after reassembly.

Key words: metro station, confined space, disassembled shield, station passing