DUCT SLEEVE FOR INCREASED PORT OF MANHOLE

摘要

PURPOSE:To improve a resistance plate to be provided for the peripheral side of a dust sleeve for increased port of manhole. CONSTITUTION:A through hole 4 is formed in a given position of an underground structure such as existing manhole 1, and a pipe is provided to insert a communication cable into the hole 4. The pipe is penetrated from the inside to the outside of the manhole 1 for the increased port of the duct. For the duct sleeve 5 for the increased port to be fixed to the manhole 1, resistance plates 8 and 9 slightly projected from the peripheral side are provided at almost equal interval in the circumferential direction.