| 摘要 |
PURPOSE:To build a vertical pit for a manhole simultaneously with building of a horizontal tunnel by a shield construction method, by a method wherein a vertical pit for a manhole is excavated through the inside of a segment for the horizontal tunnel by means of a cover supporting cylinder and a manhole peripheral wall pushing-up cylinder. CONSTITUTION:A horizontal tunnel is built in a ground by a shield construction method, an opening for a manhole is previously formed in a segment 2, communicated with a manhole 25, of segments used for construction of the horizontal tunnel, the opening is closed with a cover 4 during shield excavation, and the cover 4 is supported by means of a supporting means. After the horizontal shaft is built, the cover 4 is supported by a center cylinder 13 to remove the supporting means. After 2 split semicylindrical manhole peripheral walls 18 are assembled together on the outer periphery of the cylinder 13, the peripheral walls 18 are gradually pushed up to a ground by means of a peripheral wall pushing- up cylinder 16. The inside of the peripheral wall 18 is excavated from the horizontal shaft side, and a manhole cover 25 is placed on the top part of the peripheral wall 18. |
