| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a ground improvement device that easily and securely prevent pollution diffusion in water, can securely improve the water bottom ground at low cost, and can maintain a peripheral environment in an excellent state during over-water construction.SOLUTION: A ground improvement device 10 that has an agitation blade 22 fitted to a tip side of a rotary shaft 20 and a cylindrical pollution prevention frame 30 with a ceiling part 31 fitted so as to cover the agitation blade 22, and improves the ground by moving up and down the rotary shaft 20, and agitating and mixing the water bottom ground C by the agitation blade 22 while discharging a solidification material is provided with an insertion hole 33 into which the rotary shaft 20 is inserted at the ceiling pat 31 of the pollution prevention frame 30, and also provided with a seal material 34 which seals a gap between the insertion hole 33 and the rotary shaft 20. Further, the ceiling part 31 of the pollution prevention frame 30 is provided with an air vent 36 and also provided with a selector valve 37 which opens and closes the air vent 36.</p> |
