| 摘要 |
<p>PROBLEM TO BE SOLVED: To easily position a pipe body in a specified position in a ditch. SOLUTION: Spacers 10L, 10R are respectively integrated back to back with both of the one-side side part and opposite-side side part of a pipe body in the direction of ditch width W1, and the width of the integrated part with the spacers 10L, 10R in the integrated pipe body is made substantially equal to the ditch width W1 in a predetermined position of submerging the pipe body. The projecting quantity W2 of one side spacer 10L from the side face of the pipe body is made equal to the projecting quantity W3 from the other-side side face of the pipe body. The integrated pipe body is then fitted into the ditch and immersed in a stable liquid B, and the pipe body is positioned at the center in the direction of the ditch width W1.</p> |
