Development of a dynamic model for a cone bolt

To ensure safety in underground excavations, it is important that the support systems used are capable of resisting the dynamic loads produced, for example, by rock bursts. In this paper, a dynamic simulation model for a cone bolt is proposed based on an experimental study. Drop weight tests were performed on resin-based cone bolts. These experiments revealed that the bolt has two energy absorption mechanisms: sliding in the resin and plastic deformation. To simulate this behaviour, a two degrees-of-freedom lumped-mass model is proposed. Experimentally, the proportions of sliding and plastic deformation were found to vary significantly from one test to another. To account for this variability, two methods are proposed to determine the value of the parameters governing the sliding of the bolt in the resin, whereas a dynamic force-elongation model is used to simulate the plastic deformation. Comparing the results of a simulation to experimental data proved that the constitutive elements of the model are appropriate to simulate the dynamic response of the cone bolt.