STEEL PIPE HEAD PART ATTACHMENT, WATER INJECTION STRUCTURE TO STEEL PIPE INSIDE, STEEL PIPE STRUCTURE AND PRESS-IN METHOD OF STEEL PIPE

摘要

PROBLEM TO BE SOLVED: To provide a water injection structure capable of simultaneously advancing water injection work to a steel pipe in parallel, without interrupting press-in and center digging.;SOLUTION: A steel pipe head part attachment 1 being one example of the water injection structure, comprises a cone-shaped guide part capable of guiding a drilling unit in the steel pipe inside direction and a cylindrical connection part for connecting the attachment to a steel pipe head part. The cone-shaped guide part is formed with a water filler 16 forming water injection means. The water injection means is constituted without projecting inside so as not to hinder ascent/descent operation of the drilling unit passing through the steel pipe inside. According to such a water injection structure, since the ascent/descent operation of the drilling unit passing through the steel inside is not hindered, water injection into the steel pipe inside can be simultaneously advanced in parallel to the center digging of the steel pipe. Thus, even when injecting water in press-in of the steel pipe, since there is no need to wait for water injection completion by interrupting center digging work, the extension of construction time by waiting for water injection can be avoided, and the press-in of the steel pipe can be efficiently advanced.;COPYRIGHT: (C)2015,JPO&INPIT