| 摘要 |
PROBLEM TO BE SOLVED: To provide a technology enabling a shaft exeavation method with using a large cylindrical casing not transportable in a general road due to the load traffic act. SOLUTION: A cylindrical casing forming apparatus 10 is provided with an impact head 13 actuated with a hydraulic jack 12 and two pieces of semicylindrical receiving hardwares 14 arranged in parallel to the impact head 13, a peripheral wall of a cylindrical body 22 is held between the impact head 13 and the receiving head ware 14, by pressing/deforming the peripheral wall of the cylindrical body 22 with the impact head 13, a cross sectional shape of the cylindrical body 22 is deformed from an oval shape to a round shape.
|
