| 摘要 |
<p>PURPOSE:To shorten a term of work in field work by substantially increasing plant manufacture of a mold form of a structure. CONSTITUTION:A double-pipe unit 1, comprising an outer cylinder 2 and an inner cylinder 3 inserted fitted to the inside of this outer cylinder 2 through a concrete driven layer 6 and further to provide connection parts 8 of piping, electric wire cable, etc., and maintenance passages 10 in the inside, is buried in the ground. Concrete 13 is placed in the concrete placed layer 6 from an upper part of the outer cylinder 2.</p> |
