| 摘要 |
PROBLEM TO BE SOLVED: To provide a steel pipe for natural ground reinforcing, which is not broken from a screw joint portion by pressure of the natural ground.SOLUTION: The steel pipe for the natural ground reinforcing includes a general part 2 of the steel pipe and the screw joint portion 6 provided on both ends of the general part 2. The screw joint portion 6 is made to have tensile strength higher than that of the general part 2. Specifically, at least either of the thickness or the material of the screw joint portion 6 is thicker or harder respectively than that of the general part 2. As the screw joint portion 6 is not broken by the pressure of the natural ground, the natural ground can be kept in a stable state. |
