摘要:
A shield excavator (4) is mounted in a seal body (9) which is rotatably mounted in a cylindrical skin plate (5) supported by a shield frame (8). A shaft (1) is excavated by propelling the shield frame (8) downwards and the seal body (9) is then pivoted in the skin plate (5) to orient the shield excavator (4) substantially horizontally and the shield excavator (4)is then propelled through an opening (26) in the side of the skin plate to excavate a tunnel (2).