Dynamic inflatable, friction rockbolt for deep mining

摘要

DSI Underground developed a bolt, based on a frictional, inflatable bolt combined with an internal additional load-bearing element, called the Dynamic Omega-Bolt. This paper provides technical detail of the bolt design and the results of laboratory tests of its performance. Laboratory drop tests conducted at the CanmetMINING laboratories suggest that under dynamic loading, the bolt exhibits a peak tensile strength based on the frictional element combined with a residual loading capacity from the internal element. Failure of both elements of the bolt corresponds to an average absorption of 35 kJ of energy due to steel elongation. The residual loading capacity is in the range of 70 kN and it is intended to retain the dead load of broken rock slabs generated by an event of a sudden release of energy, as long as sufficient friction bond length is retained at both ends of the bolt. The Dynamic Omega-Bolt associates the well-known advantages of inflatable friction bolts such as fast, clean and safe installation, with an improved capacity of energy/deformation absorption from the internal point anchored element.