The UniPass Yielding Bolt is is intended for use in yielding (also known as converging) ground conditions.
The bolt has three sections:
- A threaded bond section at the far end of the bolt, which provides foot anchorage
- A smooth yielding section in the middle of the bolt
- A threaded bond section at the near end of the bolt
The yielding section comprises a smooth ductile steel tube, which easily de-bonds from the surrounding resin or cement grout.
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, which minimises the annulus around the bolt, providing optimal bonding and reducing grout consumption. A range of cross and button drill bits is available.
The bolt can also be installed in pre-drilled holes.
The grouting agent (CarboThix resin or cementitious grout) is injected through the central hollow section of the bolt into the borehole and fills the annulus between the bolt and the borehole wall.
- Easy and fast installation
- Cost - effective
- Corrosion protection available
- Energy absorption occurs in the bolts defined smooth yielding section and does not compromise the anchorage capacity of the bond sections
- Developed for applications in hard rock mining and tunnelling
- Ideal solution for applications in difficult ground conditions, including broken ground and collapsing boreholes
- High advance rates in one step self-drilling mode
- Injectable with bulk resin or cementitious grout
- Extensively tested in the field and laboratories
- Proven system being applied in various mines around the globe
- Various configurations available to meet local requirements
