SOIL IMPROVEMENT AND SOLIDIFIED WALL CONSTRUCTION DEVICE

PROBLEM TO BE SOLVED: To secure vertical accuracy of an improved body by arranging a nozzle so as to point to the earth-sand excavating part from the outer periphery of earth-sand cutting drums, and arranging a solidifying material supply means to supply a slurry-like solidifying material to the nozzle under high pressure. SOLUTION: When an improved body is constructed adjacently to an existing structure, a support frame 17 is hung down to a place separate by the prescribed length from the existing structure. Next, excavation is propelled vertically downward by rotating cutter drums 12a, 12b by a hydraulic motor 11. Next, when the cutter drums 12a, 12b reach the expected depth of a foundation improvement, the cutter drums 12a, 12b are rotated while raising the support frame 17, and at the same time, a cement liquid is forcibly sent up to a high pressure injection nozzle 15 from a supply device to be injected from the cutter drums 12a, 12b. The injected cement liquid also excavates the surrounding ground, and cutting earth-sand and the cement liquid are mixed together to form an improved body. Vertical accuracy of the improved body can be easily secured thereby.