To provide a partial double-tube lock bolt construction method using a drilling rod, which is effective for the case that a drilled wall cannot be self-supported because of bad geology resulting in difficult single-tube drilling.
At the front end of the drilling rod 11, a drilling lost bit 13 is mounted which has a diameter somewhat larger than the outer diameter of a short guide tube 14 to be driven at the same time. The front end of the short guide tube 14 is opened at a certain distance therefrom. In the state that a centralizer 17 is arranged in an opening portion or its vicinity, the short guide tube and the drilling rod inside thereof are driven to drill a hole up to a depth equivalent to the length of the short guide tube. Then, only the drilling rod is additionally driven. Solidifying material is pressed and filled through an inner hole of the drilling rod from a discharge port of the front end lost bit into the formed drilled hole. After finding return C of the solidifying material from the drilled hole (a) to the base end of the short guide tube 14, a predetermined amount of solidifying material is further pressed actively thereinto through the inner hole of the drilling rod 11 and a pressure filling port 16a of the short guide tube 14 in the state of closing a mouth portion.
| JP2004137760A | 2004-05-13 | |||
| JP2002038865A | 2002-02-06 | |||
| JPS5367925A | 1978-06-16 | |||
| JPH07216883A | 1995-08-15 | |||
| JP2000008388A | 2000-01-11 |
Torii Kazuhisa
Takayoshi Tagawa
Higashio Masahiro