PURPOSE: To shorten the execution time for ground treatment at mixing hardening material in soil by enabling to form a ground treatment part out of an intrusion process and a drawing out precess while discharging a part of soil of the original ground.
CONSTITUTION: A treatment device is constituted of a rotary shaft 1 provided with stirring blades 4 on the lower part side, a hollow pipe 2 formed with an opening end 2a downward, a drilling blade 9, and a screw auger 8 provided with a screw 8, and the rotary shaft 1 and the screw 8 are elevatably, normally, and reversely rotated by means of a rotation drive part 5. During the intrusion process of the rotary shaft 1, the soil at the opening end 2a of the hollow pipe 2 is only discharged by means of the screw 8, at the same time hardening material is forcedly fed through a feed pipe 6 and discharged from the discharge ports of the stirring blades 4, stirred with the soil, and a treatment intermediate part is formed. During the drawing out process, the hardening material is similarly forcedly fed through the feed pipe 6, the hardening material discharged from the discharge ports of the stirring blades is injected to the treatment intermediate part, so as to form the ground treatment part.
FUDO GIKEN KK