Abstract: The rapid tunneling mode conversion technology of parallel dualmode shield used in Wuyi Overpass StationXinxiu Park Station Section on Nanning Metro Line No. 5 is introduced. The slurry mode and earthpressure mode of the dualmode shield can be available separately. The cooperation of two series of mucking system can improve the soil in chamber to meet the mucking requirement of screw conveyor and slurry pipe, which can guarantee the mode conversion by soil conditioning. Two times of mode conversion of the shield have been conducted within plan, and 12 times of experimental mode conversion have been conducted; no slurry gushing of screw conveyor of slurry pipe block occurs, and the surface settlement has been effectively controlled.

Key words: slurry/earthpressure dualmode shield, tunneling mode conversion, ground conditioning, soil chamber pressure, bypass mode