Abstract: The causes for the malfunctions of the drive sealing of screw conveyors of shield machines, such as irrational screw conveyor design, inclining of screw rod, damage of contacting surface of the screw conveyor case, leaping forward of the screw rod and inadequate grease injection, are analyzed, and countermeasures, including screw conveyor structure optimization, ground conditioning, rationally selecting the screw conveyor speed, avoiding boring with empty chamber and controlling the manufacturing process, are proposed, with the practice in Chongqing as an example. The paper can provide reference for the coping with the malfunctions of the drive sealing of screw conveyors of shield machines in similar projects in the future. 

Key words: shield machine, screw conveyor, sealing failure, countermeasure 