| 摘要 |
PURPOSE:To improve verticality, by a method wherein a rotary excavating shaft is coupled to the forward end of each of plural rotary shafts, each being supported to the mast of a ground improving device and parallel to the axis of the mast, so that the forward end of the rotary excavating shaft points to the axis of the mast. CONSTITUTION:Plural rotary shafts 1 are supported in parallel to the axis of a mast 2 to the mast 2 of a ground improving device through their respective bearings 3. A rotary excavating shaft 8, provided with agitating blades 5 and excavating blades 6 and supported to the mast 2 through the medium of a bearing 7, is coupled to the forward end of the rotary shaft 1 through a rotary thruster mechanism 4 so that a forward end 8a points to a central axis 2a of the mast 2. This causes a force to be always be exerted on the forward end 8a of the excavating shaft 8 toward the mast central axis 2a from a ground during excavation, resulting in improvement of verticality of the ground improving device. |
