LIFT PREVENTING STRUCTURE OF MANHOLE AND LIFT PREVENTING METHOD FOR MANHOLE

摘要

PROBLEM TO BE SOLVED: To achieve prevention of lift of a manhole while avoiding interference with underground utilities around the manhole.;SOLUTION: The lift preventing structure of a manhole 1 is constructed in such a way that an overhanging body 2 is disposed on the outer periphery of the bottomed, cylindrical manhole 1 and a lift preventer 3 is disposed to provide a cover above the overhanging body 2. The overhanging body 2 has a base area 2A fixed to the outer periphery of the manhole 1, and an overhanging body extension area 2B which is disposed above the base area 2A to extend vertically. The lift preventer 3 is disposed with a vertical air gap 4 formed between the lift preventer 3 and the overhanging body extension area 2B. On the occurrence of an earthquake, the overhanging body extension area 2B is allowed to come in contact with the lift preventer 3, at which the weight of the lift preventer 3 and of backfill soil on the lift preventer 3 prevents the manhole 1 from lifting.;COPYRIGHT: (C)2010,JPO&INPIT