To provide a sheath pipe for drawing into large pipe line and its drawing-in work execution method for a flexible corrugated drawn-in sheath pipe drawn in a laid large pipe line 1, which easily removes biting even if biting occurs during drawing-in and also avoids meandering by reducing biting strength of a crest part and a root part of each sheath pipe when drawing in a second corrugated drawin-in sheath pipe and following pipes.
This drawn-in sheath pipe 2 is formed in spiral or perpendicularly to a pipe axis so that a crest part 20 and a root part 2 of paralleled shape with a fixed sectional area alternately positioned at an outer circumference part. The root part 21 is formed so that a narrowest part width Sw is smaller than a top width Tw of the crest part 20. A work execution method for the drawn-in sheath pipe 2 is that a second drawn-in sheath pipe 2 and the following pipes are drawn into a large pipe line in a tension of 0.1 kgf/m or more while bring them into contact with the already drawn-in sheath pipe 2.
NISHIYAMA HIDEMI
FUKUNAGA TAKAO
