The UniPass dynamic bolt is intended for use in dynamic conditions and in areas where there is a risk of rock burst.
The bolt has three sections; a threaded bond section, a smooth yielding section and a threaded bond section.
The yielding section comprises a smooth ductile steel tube, which easily debonds from the grout and absorbs energy during a dynamic event. The bond section at the near end is optional and can be as short as 200 mm, providing sufficient space for the plate and the nut.
The bolt can be installed in self drilling mode using a sacrificial drill bit (one step method) with the drill bit welded to the bolt, providing optimal bonding and reduced grout consumption. The bolt can also be installed in pre-drilled holes.
The grouting agent (CarboThix resin) is injected through the central hollow section of the bolt into the borehole and fills the annulus between the bolt and the borehole wall.
Bolt Type | Ultimate Load (kN) (1) | Yield Load (kN) (1) | Elongation (mm/m) (2) |
---|---|---|---|
R28/150 | 220 | 170 | 150 |
R28/200 | 210 | 145 | 200 |