ABSTRACT
The range of rockburst source and damage mechanisms that are believed to occur in deep level hard rock mines will be described. One of the damage mechanisms considered to be particularly severe is that of ejection of blocks or slabs. From observations and interpretations of rockburst occurrences, typical ejection velocities in significant ejection events are estimated to be of the order of 5 to 10 m/s. Thoughts on source mechanisms associated with the ejection damage mechanism are presented.
The design of rock support capable of containing damage of this nature will be described. In addition the results of tests on yielding and conventional rockbolt elements, under simulated rockburst loading, will be described. These tests are very graphic in demonstrating the inadequacy of conventional rockbolt support elements in rockburst situations, and also provide useful design information.
