| 摘要 |
PURPOSE:To exactly improve soft ground according to the hardness of the ground by a method in which soil quality conditions are stored in a controller in advance, and the amount of a grout to be injected and the degree and range of stirring of a grout and soil and sand are controlled based on the output of the controller. CONSTITUTION:Data on soil quality conditions obtained by boring are stored in a control and administration device 1 in advance. After excavation is made to a given depth, a command is given to an oil unit while pulling up an excavator, a center hole jack 9 is vertically moved, and the rotation angle of a variale blade 11 is changed through an inner tube 8, a connection lever 15, and an interlocking part 16. Cement mortar as a grout is jetted from the lowermost end of the inner tube 8, and while an outer tube 7 is turned and soil and sand and the cement mortar are mixed by the variable blade 11, the inner tube 8 pulled up to the ground's surface. In this case, on data stored on the control and administration device 1, the amount of the mortar to be injected by the mortar unit 3 is controlled according to the depths of the outer tube 7 and the inner tube 8, and a driver 6 and the jack 9 are controlled through the oil unit 5 by the controller 2. |
