An experimental study of shear deformation behavior of rockbolt under dynamic loading

Rockburst is a form of strain energy released suddenly that is often associated with the stress concentration within a rockmass during mining excavation or blasting. In order to evaluate the shear deformation behavior of a rockbolt installed in a jointed rockmass under rockburst conditions, a series of dynamic impact load tests was undertaken involving a drop weight of 185 kg falling from a height of 2.8m equivalent to an energy level of 5076 Joules. The test sample comprised a double shear test system, with three blocks joined together with a rockbolt at various configurations. The test sample was constrained within a steel box arrangement to provide confinement. A high-speed video camera was used to record each test with impacting, and impact displacement and acceleration recorded at the same time. By evaluating their shear load-displacement characteristic, the deformation and energy absorption characteristics of the rock support system under impact shear loading could be studied.