| 摘要 |
PURPOSE:To eliminate the need to treat excavated soil by a method in which an excavating cylinder having a spiral blade on its cylinder outer wall with an excavating blade is lowered while being turned to excavate a pile pit in such a way as to coat and bond excavated soil to the wall of the pit. CONSTITUTION:A spiral blade 6 of a projected width of 20-30mm. is provided to the outer wall of a 1-2m length excavating cylinder 1 whose tip is closed, having an excavating blade. The excavating cylinder 1 is lowered while being turned and also while jetting water or compressed air from a nozzle 7 on the tip as needed in order to excavate a pile pit 2. The excavated soil is pushed up by the spiral blade 6 and closely coated and bonded to the projected wall side through a small aperture between the inside of the pile pit 2 and the outside of the cylinder 1. Therefore, the pile pit 2 having an uniform and high-dense coil layer 3 is protected from degradation, the need to treat the excavated soil can be eliminated, and the drawing of the cylinder 1 and penetration of concrete pile 4 are made easier. |
