When walking along wet sand at the beach, the wet sand around your foot appears to dry up; this phenomena is known as the Stress-Dilatancy principle and was first analysed by the well-known scientist, Osborne Reynolds.

As the dense sand is subjected to shear stress, the sand will undergo volumetric expansion (i.e. an increase in void space), and consequently the water will rush into these newly created voids. This explains why, on the surface, the sand will appear to have dried up.   The mechanisms responsible for stress-dilatancy transpire on the microscale, whilst hidden in at other length scales.
This project aims to analyse the underlying microstructure by establishing the mechanics at the level of the constituent grains - specifically force transmission at the grain-grain contacts and associated local void growths, ultimately developing equations that describe the correlation between dilatancy and material strength subjected to shear.