| 摘要 |
PROBLEM TO BE SOLVED: To provide a ground excavation device capable of easily installing a drain pipe in the ground even when a hard layer is formed in the ground and a construction method of the drain pipe using the device.SOLUTION: A ground excavation device 1 drives an auger by rotation by drive of an excavation motor 31 and drops the excavation motor 31 by drive of a drop motor 21, is constituted by arranging an extension mast which projects upward from an upper end of a column 3 and whose projection length can be varied and adjusted to the column 3, and arranging a pulley on an upper end of the extension mast, in which a second pulley is arranged at a middle part on a lower end on the rear surface of the column 3 to be freely rolled, the excavation motor 31 is constituted by being fitted to an elevation member 25 via rotary shafts 28, 29 having length in the vertical direction, and is constituted by being movably supported centering on the rotary shafts 28, 29. |
