IMPROVEMENT BODY ESTABLISHMENT METHOD

摘要

PROBLEM TO BE SOLVED: To provide a method for establishing a columnar improvement body of a layer structure and a columnar improvement body of the whole area improvement intentionally regularly sandwiching unimproved soil by a plate-like improvement body, by establishing an improvement area of the predetermined length even when inserting a rod.SOLUTION: The predetermined number of injection nozzles are provided for injecting a hardener liquid jet flow at a predetermined angle in the horizontal direction of the rod under high pressure into a tip part peripheral surface of the rod 1, and an insertion time spiral improvement area of spirally continuing a plate-like improvement body at a predetermined interval is established by simultaneously inserting by the predetermined length at a predetermined speed while rotating the rod at the predetermined speed in clockwise rotation or counterclockwise rotation while injecting the hardener liquid jet flow from the injection nozzles. and then, a pull-up time spiral improvement area of spirally continuing the plate-like improvement body at the predetermined interval is established by simultaneously pulling up by the predetermined length at the predetermined speed while rotating the rod at the predetermined speed in the clockwise rotation or the counterclockwise rotation while injecting the hardener liquid jet flow from the injection nozzles, and the insertion time spiral improvement area and the pull-up time spiral improvement area are crossed and connected at the predetermined interval.