An apparatus for improving soft ground, in which cement slurry is vigorously
discharged
from an injection rod by highly pressurized air, thus allowing hardening agent
to evenly infiltrate the soft ground, is disclosed. The apparatus includes an injection
rod (20) having an injection pipe (10) into which fluid is introduced,
and an outer casing (12) disposed around the injection pipe (10)
with an air feeding path (14) therebetween, one or more injection holders
(40) coupled to an outer surface of the outer casing (12) to be positioned
at different levels and to be inclined downward, and a bit (30) coupled
to a lower end of the injection rod (20), and having jet holes (60, 60a),
which are inclined downward and in which inclined jet nozzles (70, 70a)
are inserted, and a cutting water nozzle (74) provided at its center.
