| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce cost for burying the main and to shorten a construction period without requiring lining in an area in where the main can be buried. SOLUTION: A sleeve pipe burying ditch 2 is excavated in a section incapable of ensuring a permanent working zone in the burying area of the main 4, and a sleeve pipe 1 connected with a sleeve pipe joint hand 3 is buried in the ditch. The first main 5 having a hanger 25 on the front end thereof is cast on a plurality of roollers provided in the main casting ditch 7, the first main 5 is overhung in a pipe hanging device 8 installed in a connection place in parallel with the main casting ditch 7, and a drawing rope 22 of a pipe drawing device 21 installed in a piping drawing ditch 20 is moored at a hanger 26 of the main. Then, the second main 5 is cast in the main casting ditch 7, it is welded to the first main 5, a welded part is drawn inside the sleeve pipe 1 so that it is positioned to the end of the connection place 6, until the nth main 5 from the third main 5, the main casting/overhanging, welding and drawing are repeated until the first main reaches the side end section of the piping drawing ditch 20 of the sleeve pipe 1 and until the nth main 5 is positioned to the side end section of the connection place of the sleeve pipe 1, and a plurality of mains 5 to be welded to connect are inserted in the sleeve pipe 1.</p> |
