Surfacing prevention structure of manhole and surfacing prevention manner of manhole

摘要

PPROBLEM TO BE SOLVED: To suppress the lifting of a manhole without being affected by the shape thereof. PSOLUTION: In a lift suppressing structure of a manhole, an extension body 2 is installed on the outer peripheral wall of a bottomed cylindrical manhole, and a lift suppressing body 3 covering the upper part of the extension body 2 is disposed. The extension body 2 includes a base area 20 fixed to the outer peripheral wall of the manhole and a projection 21 which is formed to project from the inner peripheral surface of the base area 20 and engaged with the step of a tilted part on the upper side of the outer peripheral wall. On the other hand, the lift suppressing body 3 is disposed on the extension body 2 while forming a gap 4 in the vertical direction. By bringing the extension body 2 into contact with the lift suppressing body 3 in an earthquake, the lift of the manhole 1 is suppressed by the weight of the lift suppressing body 3 and the weight of the backfilled soil on the lift suppressing body. In this case, the fastening force of the extension body 2 and the manhole is increased since the tilted part is engaged with the projection 21. PCOPYRIGHT: (C)2011,JPO&INPIT