| 摘要 |
PURPOSE:To facilitate execution along a sharp curve by forming a skin plate in a shield body of a flexible pipe and drawing a wire provided in the skin plate with a traction means to bend the shield body. CONSTITUTION:A traction means 6 is adjusted to equalize the length of each wire 4 in straight execution. A skin plate 1a is formed into a straight cylinder- like form to be propelled in a shield body l and excavate a facing with a cutter head 2. In the execution along a sharp curve, a wire 4 located on the inner diameter side of the sharp curve is drawn by a traction means 6 to contract an expansible member 1c for bending the shield body l. Under such a condition, tunneling along the sharp curve is executed by excavating with the cutter head 2 while propelling the shield body l, so that the execution along the sharp curve needs hardly surplus excavation and the efficiency of excavation can be improved. |
