Experimental study on mechanical response of anchored fractured coal under cyclic dynamic loading

In order to understand the mechanical response and failure characteristics of anchored fractured coal body under cyclic dynamic load, the dynamic load impact test of anchored fractured coal under cyclic impact dynamic load was carried out by using the split Hopkinson pressure bar test system. The effects of cyclic dynamic load times and dynamic load impact strength on the stress-strain curves, bolt axial force and macroscopic failure of anchored fractured coal were analyzed. The results show that with the increase of dynamic load strain rate, the strength of anchorage specimen increases, but with the increase of dynamic load impact times, the strength of anchorage specimen decreases. When the impact input energy is constant, with the increase of impact times, the internal cracks of coal gradually expand or even fail, and the limiting force of bolt on coal expansion decreases. Under high energy impact, the bolt cannot hinder the initiation and expansion of the internal cracks in the anchored fractured coal body, and the overall instantaneous failure of the anchored coal body is prone to occur.