| 摘要 |
PURPOSE:To improve strength, by a method wherein a core rod, having a bit at its forward end, is inserted in a rotary body provided at its outer periphery with a spiral vane, and a locking part for locking a screwing tool is mounted to the rotary body. CONSTITUTION:A core rod 12 having a bit 11 at its forward end is inserted into a hole in a rotary body 14 which is provided at the outer periphery of a pipe 15 with a spiral vane 16, and the pipe 15 is placed on a stopper plate 11a of the bit 11. A screwing tool 4 is attached to the core rod 12, and the lower end of the screw tool 4 is inserted inwardly of the pipe 15. With the screw tool 4 rotated by a proper device, the rotary body 14 is turned, the rotary body 14 is thrusted in a ground through rotation of the vane 16, and the core rod 12 is also buried. A retaining tool 13 is then secured to the top end of the core rod 12, and a stay wire is locked to the retaining tool 13. |
