| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method of removing an underground obstacle, capable of reducing an excavation amount on the inner peripheral side in a casing as much as possible and surely gripping and removing an underground obstacle inside the casing even when an excavation space formed inside the casing is filled with excavation debris. <P>SOLUTION: A lifting device 1 is inserted into a casing 17 where the underground obstacle is excavated, the lifting device 1 is fixed to the casing 17 by opening a holding arm 3 at an insertion position, and the lifting device 1 is pushed in while being rotated together with the casing 17. The outer periphery of the underground obstacle positioned inside the casing 17 or the periphery is scraped off over a prescribed length from an upper end by a cutting bit 16 provided on a holding pawl of the holding arm 3, and the underground obstacle is held by the holding pawl of the holding arm 3 after the rotation of the casing 17 and push-in are stopped. Thereafter, the underground obstacle positioned inside the casing 17 is lifted by the lifting device 1 and taken out of the casing 17. <P>COPYRIGHT: (C)2012,JPO&INPIT |
