| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a hydraulic steel pipe capable of certainly preventing collapse of it due to an external hydraulic load by reinforcing structure to perform facilitation of manufacture as well as reducing cost by reducing weight of a steel material required for reinforcement. SOLUTION: Six pieces of metallic small pipes 3, 3... are installed on an outer peripheral surface of a hydraulic steel pipe 1 with equal intervals in the circumferential direction by extending them along overall length in the axial direction. A plural number of introduction holes 4, 4... are provided through a peripheral wall on these small pipe 3, 3... with intervals L in the axial direction. Consequently, it is possible to prevent collapse of the hydraulic steel pipe 1 due to an external hydraulic load by reducing external hydraulic pressure to be loaded on the hydraulic steel pipe 1 by flowing down and discharging water on the outside of the hydraulic steel pipe 1 by introducing it to the insides of the small pipes 3, 3... from a plural number of the introduction holes 4, 4....</p> |
