| 摘要 |
PURPOSE:To excavate the ground in polygonal shapes. CONSTITUTION:Four-spoke type excavators 3a, 3b... are provided to the front of an excavating part of a shield machine 1. Motors driving the excavators 3a, 3b... and jacks 9 for propulsion are provided inside a shell 5, and a rectangular cylindrical tail plate 11 is attached to the rear side in the shell 5. While excavation is made with the excavators 3a, 3b... of the shield machine 1, the shield machine 1 is moved forward as a whole with the jacks 9. In excavation executed with the shield machine 1, an excavation area 13 becomes approximately rectangular with its outer periphery becoming wavy. Segments in flat plate- like shape 15 and in L-shaped section 17 are combined to form a rectangle, and back-filling materials 20 are injected through injection ports 19 to a gap between the segments 15, 17 and the excavation area 13. |
