In order to better study rock blasting mechanism better in layered rock strata, the dynamic tensile mechanical characteristics of the carboniferous shale surrounding rock mass around the Sujiayan tunnel were explored, which belongs to the north section of the Zhengwan high-speed railway project in western Hubei Province. To reveal the effects of impact angle and velocity on the dynamic tensile strength and corresponding failure mode of carbonaceous shale, dynamic Brazilian splitting tests were carried out under five impact angles (0°, 30°, 45°, 60° and 90°) by the split Hopkinson pressure bar (SHPB) device with a high-speed camera and the digital image correlation technology (DIC). At the same time, different impact velocities for every impact angle were also tested by three impact pressures (0.1 MPa, 0.2 MPa and 0.3 MPa). The results show that the dynamic tensile strength of the shale decreases first and then increases with the increase of impact angle under different impact velocities. The minimum value is reached when the impact angle is 30° and the maximum value is reached when the impact angle is 90°. The dynamic tensile strength of shale presents a significant anisotropy, and the degree of anisotropy decreases with the increase of impact velocity. With the increase of impact velocity, the dynamic tensile strength of shale increases correspondingly, and there is a significant linear relationship between the dynamic tensile strength and impact velocity. In addition, both impact angle and impact velocity have a great influence on the dynamic tensile failure mode of shale.

carbonaceous shale  /  split hopkinson pressure bar  /  dynamic brazilian split  /  dynamic tensile strength  /  dynamic tensile failure mode