Research on the effect of surface retaining elements on the dynamic load resistance of bolted rock

The failure of support systems in deep coal mine roadways is a critical issue that hinders the development of deep coal resources. As a critical support element, the surface retaining element (SRE) plays a more prominent role in deep conditions. A comprehensive investigation into the anti-impact mechanism of an SRE on bolted surrounding rock under a dynamic load is greatly needed. In this study, split Hopkinson pressure bar (SHPB) tests were conducted to investigate the strengthening effect of different SRE areas on the mechanical properties of bolted specimens under dynamic and static loading. Moreover, the reinforcement effect of the SRE on the surrounding rock under various dynamic loadings was examined by FLAC3D. The results indicate that increasing the SRE area enhances the overall mechanical properties of the bolted specimens under combined dynamic and static loading conditions. By constructing an engineering-scale roadway numerical model, the impact of the SRE area on the amount of roof subsidence increases with increasing dynamic loading. The research findings enrich the study of the bearing capacity of SREs on bolted surrounding rock and provide a theoretical basis for controlling the surrounding rock in deep dynamic load roadways. • The mechanical behaviors of 3D-printed rock exhibited similarities to soft rock, validating their applicability in rock mechanics research. • Enhancing the area of surface retaining element (SRE) can effectively improve the dynamic mechanical behaviors and integrity of the bolted specimen. • SREs demonstrated a more pronounced inhibitory effect on plastic failure in roadway surrounding rock under intense dynamic load disturbances.