OMITTED

摘要

The present invention relates to a sectional division construction type non-excavation inner surface maintenance method for a medium-large caliber duct. The method comprises: a process of cleaning a duct; a process of filling the inside of the duct with a filler for the bottom of a connector in the shape of an empty space part of a cross section of the duct; a process of manufacturing an arc filler for the top of the connector by filling the inside of a spring-mounted cylindrical cover with a liquid filler for the top of the connector; a process of inserting the arc filler into the top of the connector of the duct in a ∩-shape; a process of filling the empty space between the inner surface of the duct and the bottom of the arc filler with a post filler for the top of the connector; a process of applying a coating material to the post filler for the top of the connector and the filler for the bottom of the connector; and a process of completing maintenance. Therefore, the present invention is capable of improving the quality of maintenance as well as constructability.