Deformation prevention method and apparatus of the tail plate of large cross-section rectangular shield machine

摘要

PURPOSE: To prevent deformation of the tail plate of a large-cross-section rectangular shield machine. CONSTITUTION: On the inner peripheral surface of the tail plate 1 of a large- cross-section rectangular shield machine and in a position where a support material 11 transfers an external force to a segment by abutting to the segment supported from inside by a preassembled shape retainer 10, the support 11 is installed in such a way as to be capable of moving in and out in the inside- outside direction. An external force which a tail plate 1 receives when projected by an amount equivalent to a tail clearance is transferred to the segment 2. Large external forces such as earth and hydraulic pressures working on the tail plate 1 are transferred to the segment by the support material 11 to provide a supporting force, and the tail plate is made to deform as little as possible, whereby the tail clearance can be secured mechanically.