How do fabric and dilatancy affect the strength of granular materials

The paper explores the role of dilatancy on the shear strength of a granular material by highlighting both of its particulate nature and microstructure. A fabric embedded stress dilatancy equation is used in an elastoplastic model to demonstrate fabric-dilatancy related sand behaviour. The importance of dilatancy is highlighted by examining sand response along loading paths other than drained and undrained conditions. It is found that the strength of sand is not at all bounded by the ones obtained in drained and undrained conditions. It turns out that lower strengths are encountered under strain paths with forced dilation or compaction. This is confirmed by microstructural observations made on a granular assembly of photoelastic particles loaded biaxially.