Dynamic Rock Bolt


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.

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  • High Advance Rates
  • Injectable with bulk resin
  • Extensive field and laboratory testing
  • High advance rates in one step self-drilling mode
  • Injectable with bulk resin or cementitious grout
  • Dynamic capacity between 20kJ and 50kJ, depending on bolt type and configuration
  • Energy absorption occurs in the bolts defined smooth yielding section
  • Proven system being applied in various mines around the globe
  • Various configurations available to meet local requirements


Bolt Type Ultimate Load (kN) (1) Yield Load (kN) (1) Elongation (mm/m) (2)
R28/150 220 170 150
R28/200 210 145 200
All geometrical values are nominal 1) Ultimate Load and Yield Load are minimum values; cross section calculated based on nominal mass 2) Elongation of the yielding section per meter of length
Product Accessories
  • Different types of drill bits available depending on rock hardness and bolt length
  • Various shapes and thickness of plates depending on requirements
  • Standard and lock nuts