To provide a contaminated soil improving method by which decontamination of contaminated soil can be efficiently performed at a low cost by efficiently discharging the contaminated soil on the ground by high pressure injection of water and air and further injecting and replacing slurry-like replacing burying materials in a space part made by discharging the contaminated soil.
In this contaminated soil improving method, an injection pipe 2 is inserted in the ground until it reaches the contaminated soil 32, then while rotating and pulling up the injection pipe 2, water 30 and air 31 are injected from nozzles 10, 11 to agitate the contaminated soil 32, slurry-like contaminated soil 32A is discharged on the ground from a space between a hole 27 and the injection pipe 2, further slurry-like bamboo charcoal powder 16A is injected from a replacing burying material injection nozzle 13 provided below the injection nozzles 10, 11 of the water 30 and the air 31 to bury the slurry-like bamboo charcoal powder 16A into the space part made by discharging the contaminated soil 32.
SAKUMA MITSUYOSHI
SUZUKI SUKEMOTO
TOWA KK