Strength and dilatancy of sands in direct shear

This article analyses the strength and dilatancy of three sands with different morphologies using four established stress‒dilatancy theories. The morphology of granular materials, including sands, significantly influences their physical, mechanical, and hydraulic behaviour, mainly due to the influence of grain shape. Sands with more angular grains demonstrated higher strength and dilatancy than the ones with rounded grains. Analysing the influence of relative density and stress levels on the strength and dilatancy of sands in direct shear tests indicates that an increase in relative density enhances sand strength and dilatancy, while an increase in stress levels reduces these properties. The essential influence of grain morphology, relative density, and stress level on sand strength provides valuable insights for geotechnical applications concerning granular materials.