Dynamic crack propagation and energy dissipation of slate under coupled bedding and water effects

Coupled effects of bedding and water significantly influence the dynamic response and stability of rock mass structures. Layered slate served as the primary subject of this investigation. Standard slate samples with diverse bedding angles were prepared under both natural and saturated states. Impact compression tests were performed using a Split Hopkinson Pressure Bar system. High-speed photography enabled the systematic analysis of dynamic crack propagation, mechanical properties, and energy dissipation. The intrinsic influence mechanisms of water and bedding were subsequently explored. Experimental results revealed a dual effect of water on crack development. Bedding angle determined the inhibitory or promotive influence of water on crack propagation. Natural slate samples with 0°–45° bedding angles exhibited failure along the impact loading direction. Samples with 60°–90° bedding angles demonstrated failure along the bedding planes. Saturation induced failure along bedding planes for most bedding angles. Samples with a 0° bedding angle did not follow this pattern. The most critical bedding angles for natural and saturated slate were 45° and 60°, respectively. These findings provide a valuable theoretical basis for the design and construction of layered rock mass engineering.