Impact strength characteristics of granite under combined dynamic and static loading conditions

To study the impact strength characteristics of granite under combined dynamic and static loading, an experimental loading system based on the split-Hopkinson pressure bar (SHPB) was developed. Impact loading at different strain rates was performed to study the stress and strain characteristics of granite at different confining pressures. From this, the impact strength characteristics under one-dimensional combined dynamic and static loading conditions were determined. The results show that the tested sample has higher anti-impact tensile strength during combined dynamic and static loading relative to purely static loading, with an amplitude increase of 80–280%. Under the same axial load, the size of rock fragments after failure decreases as dynamic load increases. In the case of impact failure, the failure mode of the rock when subjected to combined loading is tensile, and as the impact loading rate increases, the anti-impact strength increases from 17.7 to 23.18 MPa. © 2021, Saudi Society for Geosciences.