ABSTRACT
The problem with shotcrete on rock subjected to vibrations has previously been studied in situ and through numerical modelling. Within the present project, an elastic finite element model is presented which consists of beam elements, used to model the flexural stiffness and mass of the shotcrete lining and the fractured rock. Spring elements are used to obtain elastic coupling between shotcrete and rock. The loads on the model are acceleration-time functions. Scaling laws, for the magnitude of vibration velocities in rock as a function of distance and weight of explosives, can be used to study the damage to shotcrete at various distances from the source of an explosion. Age-dependent shotcrete material properties can be varied to investigate the vulnerability of young shotcrete exposed to vibrations. The model has been verified using the results from in situ tests, with material parameters obtained from an extensive literature survey. Recommended minimum shotcrete ages, based on numerical results, are given for practical use.
