Abstract:

This study investigates the influence of normal stress and interfacial roughness on the shear mechanical properties of sand-steel plate contact interface and explores the underlying mechanisms through large-scale interface shear tests and PFC mesoscopic simulations. The findings indicate that increased interfacial roughness leads to a higher interfacial friction angle, enhanced interfacial shear strength and residual strength, and more pronounced shear shrinkage and dilatancy of the sand. As normal stress increases, interfacial shear strength and residual strength improve, shear shrinkage of the sand increases, and dilatancy decreases. During the shear process, sand particles move and aggregate in the shear direction, resulting in the merging of strong contact force chains, with a decrease in their numbers but improved force transmission performance. The interfacial roughness affects the contact area between sand particles and the steel plate by altering the number of sand particles in the steel plate grooves, thereby influencing the interface’s shear mechanical properties. Normal stress affects the compactness and contact force between sand and steel plate, leading to changes in the interface’s shear mechanical properties.

Key words: sand-steel plate contact interface, interface shear test, PFC, mesoscopic simulation, interface roughness, normal stress