Simulative Discrimination and Analysis of Clay Muck Blockage in Earth Pressure Balance Shield Chamber

Abstract:

In this paper， an evaluation index for the muck status inside chambers based on shear plate torque is proposed. Then multiple sets of model tests are then conducted to reveal the change characteristics of this index before and after the clogging of clay muck inside the chamber. Finally， a real-time method for judging the muck clogging is established. The results show that the tendency of muck adhesion gradually develops toward the cutter head after the difference appears in the angular velocity of the muck around the central axis near the partition. At the same time， muck empties at the top of the chamber. Muck blockage eventually occurred. The occurrence of the void zone is the preliminary stage of the muck blockage and can be identified by the difference between shear plate torques on the top and underside of the shield chamber.