| 摘要 |
PURPOSE:To excavate easily a tunnel of a long and circular cross section by a method in which excavation is made while moving the cutter face in the long axial direction of the skin plate in the partition wall-thrust portion of the cutter shaft. CONSTITUTION:A cutter face 12 set on the tip of a cylindrical skin plate 10 of a long and circular cross section is rotationally operated by a cutter motor 16 through a cutter shaft 14 fixed to the back of the face 12. A slider 26 is set at a portion where a partition wall 20 is pierced by the shaft 14 and excavation is made while reciprocally moving the face 12 in the long axial direction of the plate 10 to form a hole of a long and circular cross section. A segment 22 is set on the back end side of the plate 10 and a shield jack 24 is operated by using the reaction of the segment 22 for advancing the shield excavator. |
