| 摘要 |
PURPOSE:To eliminate the wasteness of operations by a method in which a washer with a bolt hole and a box-type tool to be drawn out after the hardening of concrete are coupled with each other and fixed in the concrete and a working space is formed in the inside of the manhole. CONSTITUTION:A washer metal 2 having a collar 5 formed by bending both ends of a flat plate after being bent into a recessed form and a box-shaped tool 3 are set together and holes 6 and 6' for fitting bolt are formed in them. A set of the washer 2 and the tool 3 is inserted into the recessed portion 8 of a manhole formwork ring 7, a burying nut 12 is set on the downside of the ring 7 and thrust with the fitting bolt 9, and ready-mixed concrete is placed. After the concrete hardens by curing, the bolt 9 is removed out, and the tool 3 is pulled out. Whereupon, both the collars 5 serve as anchors to the opening 11 and the bottom portion and the washer metal 2 becomes a coupler 20 in the buried fixed state. Sealants 14 are attached to uneven fitting portions 13 and 13' previously formed, and the bolt 9 is clamped by utilizing the opening 11 for connection and fixation. The clamping can thus be easily and completely attained. |
