| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve a cut-off performance by preventing opening of a closing lid or damages of cut-off packing. <P>SOLUTION: A water cut-off structure 1 includes a grout hole 10 formed passing through a segment in the thickness direction thereof and a closing lid 20 attached to a pit side opening of the grout hole 10. On the grout hole 10, a hole side flat part 11 in a smooth surface shape along an inner peripheral surface on the pit side in the axial direction is formed, and a female screw part 12 is formed closer to a natural ground side than the hole side flat part 11. The closing lid 20 comprises a head part 21 in a disk shape and a cylindrical part 22 extended from one end face of the head part 21, a male screw part 23 which can be screwed to the female screw part 12 is formed on the distal end outer peripheral surface of the cylindrical part 22, and cut-off packing 25 is provided along a circumferential direction on the proximal end side of the cylindrical part 22. In the state of screwing the male screw part 23 to the female screw part 12 and attaching the closing lid 20 to the grout hole 10, the cut-off packing 25 is brought into liquid tight contact with the hole side flat part 11. <P>COPYRIGHT: (C)2012,JPO&INPIT |
