To carry out boring well while minimizing striking force applied to an insertion pipe and to insert the insertion pipe in a borehole at the same time in a boring device used in the case of boring a hole in the advance natural ground to excavate a tunnel and inserting a reinforcing pipe in the borehole at the same time in a natural ground reinforcing method in a tunnel prelining construction method or the like.
This boring device applies rotary striking force to a boring bit B provided on the tip side of a boring rod 3, to bore a hole in the ground and pulls insertion pipes 4 sequentially into the borehole with the advance of the boring bit B at the same time. A buffer cylindrical body 6 through which the boring rod 3 is insertable, is provided between the boring bit B and the insertion pipe 4, and the buffer cylindrical body 6 is constituted to be relatively movable by a predetermined distance in an axial direction with respect to each of the boring bit B and the insertion pipe 4.
FUKUYA YOSHINORI
MIYAJIMA YASUYUKI
WAKITA SHINGO
TSUJI TAKASHI
HANEUMA TORU
KFC LTD
Shigeyuki Motoi