Crack arrest and energy absorption mechanism of anchored fractured rock mass under dynamic and static combined loading
To investigate the crack-arresting effect of rock bolts on fractured deep rock masses,dynamic-static combined loading tests were conducted under varying impact air pressures.Based on an optimized mechanical model of the bolt-rock interface,a new finite difference method-discrete element method(FDM-DEM)cou-pled numerical split Hopkinson pressure bar(SHPB)system and bolt model were developed.The mechanical properties,energy dissipation,and failure characteristics of both fractured rock masses and bolted fractured rock masses were studied.Furthermore,the anchoring mechanism of rock bolts under dynamic loads was eval-uated from the perspective of mesoscale energy dissipation for fractured rock masses.The results indicate that the dynamic compressive strengths of fractured rock masses and bolted fractured rock masses increase with higher impact air pressures.The anchoring effect of rock bolts for fractured rock masses enhances the dynamic compressive strength and reduces the post-impact damage.The energy absorptivity of bolted fractured rock masses is similar to that of intact rock masses.From a mesoscale perspective,bolt reinforcement reduces the frictional slip dissipation energy and the kinetic energy carried by fragments post-failure in fractured rock mas-ses,leading to an overall decrease in absorbed energy.
dynamic and static combined loadingfractured rockmechanical propertiesanchoring mechanismfinite difference method-discrete element method(FDM-DEM)coupling
万方数据
维普
