| 摘要 |
PROBLEM TO BE SOLVED: To provide a pipe having a double-pipe structure, capable of maintain a non-drainage structure state during propulsion to realize a sealed propulsion method to prevent collapse of the natural ground, and capable of being in a drainage structure state after the end of the propulsion to perform drainage of the natural ground.SOLUTION: A pipe includes an outer pipe 31 having a circular cross section, and an inner pipe 32 having a circular cross section, each of which has a plurality of through-holes 35 penetrating through the pipe formed therein. An outer diameter dimension of the inner pipe 32 and an inner diameter dimension of the outer pipe 31 are set so that only the inner pipe 32 can be rotated. The rotation of the inner pipe 32 using the central axis of the inner pipe 32 as a rotation center allows the pipe to be set to a non-drainage structure state and a drainage structure state. In the through-holes 35 of at least one of the inner pipe 32 and the outer pipe 31, filters 36 allowing water to pass and preventing sediments from passing are installed, respectively. The pipe has a double-pipe structure capable of maintain the non-drainage structure state during propulsion to realize a sealed propulsion method, and capable of being in the drainage structure state after the end of the propulsion. |
