| 摘要 |
PURPOSE:To prevent the occurrence of stress concentration in a thrust force transferring section even if pipes for propulsion construction method are made to propel along a curved passage. CONSTITUTION:With the deep end face 7 of the reception port 3 formed in the end section of a pipe 1 contacted by the head face 10 of the insertion port 4 of another pipe 2 to be inserted into this reception port 3, and with the thrust force from the insertion port side transferred to the reception port side, pipes are propelled along a curved-like passage under the ground. The pipe walls at the parts, which are the inside of the pipes 1 and 2, are thickened and a mechanism 12 is provided to prevent both pipes 1 and 2 from relatively rolling. Therefore, the thrust force transferring section between the reception port and insertion port can obtain a comparatively large contact area, preventing the occurrence of stress concentration. |
