| 摘要 |
PURPOSE:To miniaturize a guide pole, etc., as well as make the whole of the ground improver compact by a method in which a frame having an opening on its lower end is connected to the guide pole in a vertically movable manner, and a ground improving unit is hung down by a rope in a detachable and vertically movable manner in relation to the frame. CONSTITUTION:When a motor 33M in a ground improving unit 1 is turned, a tip bit 11 and an extended arm cutter 12 are turned, and under the condition, the unit 1 is lowered by sending out a rope R from a winch 7. In this case, the frame 6 is also lowered along a guide pole 5 to a stopper 55, and thereafter the unit 1 comes out of the frame 6 and goes down. The bit 11 and the cutter 12 penetrate under their own weights while disturbing the ground G. After a given sustratum is reached, the unit 1 is hung down while discharging cement milk from the discharge port 118m of the bit 11 and the discharge port 124m of the cutter 12 to improve the ground. |
