The Kiruna Bolt is a push in, end anchored yielding bolt. This bolt is pushed into a pre-grouted hole of the correct length. The end anchor is activated by a percussive load applied to the nut when the bolt has bottomed out at the end of the hole.
The nut is then rotated to give up to a 35kN pre-load through the mesh onto the surface of the excavation. The unit can be provided with a collapsible load indicator to confirm correct tensioning of the unit when installing. The Kiruna Bolt can be supplied in 16mm, 18mm or 20mm bar depending on requirements. The unit has an elongation of 23% in static conditions and 15% under dynamic loading.
|Bar diameter||Ø16.3mm, DIN 405 RD 18||Ø18.3mm, DIN 405 RD 20||Ø20.3mm, DIN 405 RD 22|
|Length of bolt||1.0m to 3.0m||1.0m to 3.0m||1.0m to 3.0m|
|Typical length of thread (adjustable)||150mm||150mm||150mm|
|Yield strength typical||500MPa||500MPa||500MPa|
|Yield load typical||100kN||125kN||155kN|
|Ultimate tensile load typical||140kN||170kN||220kN|
|Guaranteed static||15% to 30%||15% to 30%||15% to 30%|