The deep mixing apparatus to strengthen weak stratum and deep mixing process using that

PURPOSE: A deep mixing apparatus for soft ground improvement and a deep mixing method using the same are provided to inject a mixture required for solidification directly without preprocessing work, to heighten mixing efficiency in the depths and to form an uniform and continuous high strength underground structure. CONSTITUTION: A deep mixing apparatus for soft ground improvement comprises: an input driving motor installed to the center of a 4-axis auger; an input shaft(140) connected to the input driving motor and arranged parallel to a connection rod(120); a mixing blade(148) fixed to the end of the input shaft to scatter dropping inputs in the radial direction; a screw feeder(142) formed in the appointed length on the top of the input shaft; a housing(144) sealing up the screw feeder and fixed with a bearing at the sealed state with the input shaft, and having a discharge port(146) to be symmetric in the diametric direction; a support(150) connected to a leader to fix the housing; and an input hopper fixed to the 4-axis auger and having an input pipe connected with the housing.