INSTALLATION STRUCTURE OF RISER WITH SPIRAL GUIDE PASSAGE, AND REPAIR METHOD FOR THE RISER

PROBLEM TO BE SOLVED: To provide an installation structure of a riser with a spiral guide passage, which is equipped with a structure for preventing the lift of the riser, and which enables the operation of repairing the riser on the occurrence of troubles such as the clogging of the riser in a manhole and damage to the riser and the operation of replacing the riser in the case of a deterioration in the riser to be performed without the destruction of the manhole. SOLUTION: In this installation structure of the riser 2, a space section 3, which is formed between the riser 2 and an inner wall of the manhole 1, is filled with a filler 4 which is composed of a granular material allowing the intrusion of water into the manhole 1, and weight against buoyancy acting on the bottom of the riser 2 is provided, so that the action of preventing the lift of the manhole can be provided. A blade member 5, which is formed in an outward overhanging shape, is annexed to the outer peripheral surface of the riser 2, so as to enhance the integration of the filler 4 with the manhole 1 in the space section 3. COPYRIGHT: (C)2008,JPO&INPIT