| 摘要 |
PURPOSE:To reduce greatly a construction cost and period by arranging a plurality of excavation bits to the same shaped shell as that of a non-circular tunnel, and driving them with a driving means provided to the interface of a partition to excavate the same shaped non-circular tunnel as that of the shell. CONSTITUTION:A drawing shaft 23 is provided between vertical shafts 21 and 22, a wire 24 is passed through the shaft 23 to couple the rear end thereof with an excavator 1 through a drawing shaft end 13. After that, the end of the wire 24 is drawn by a jack 26 provided to the inside of the vertical shaft 21. Then, during the drawing, a driving motor 11 is driven to rotate excavation bits 7 at one time, and a bedrock is excavated. The earth taken into chambers 17 by excavation is stirred and mixed with muddy water delivered from a mud delivery pipe 14 to discharge it through a mud removal pipe 15. According to the constitution, a section of the shell has the same shape of a section as that of a non-circular tunnel, so that the same shape of the non-circular tunnel as that of the shell can be automatically excavated. |
