Controlling Earth Pressure of Shield Machine with Optimization Algorithm

The mechanical parameters of conditioned earth in the head chamber of shield machine are determined for computing response of conditioned earth with the speed change of screw conveyor. The relationship between the strain and the accumulating amount of earth is proposed based on Duncan and Chang´s model. The relationship between the increment of earth pressure and the angular velocity of screw conveyor is presented. The controlling model of earth pressure balance of shield machine is proposed with optimization algorithm. The proposed optimization algorithm can take account of practical constraining conditions of screw conveyor including maximum, minimum and maximum gradient of angular velocity of screw. The numerical simulation shows that the proposed control model is effective and stable for controlling earth pressure of shield machine by adjusting speed of screw conveyor.