Dilatancy (granular material) / internal erosion. The use of appropriate filters is critical to managing these materials; I like a #4 sized clear gravel / coarse-grained sand as a commercial aggregate which is generally readily available. Some non- woven filter fabrics are also suitable. As with all filters, D15 and D50 compatibility criteria should be checked. Dilatancy (granular material) Dilatancy is the volume change observed in granular materials when they are subjected to shear deformations. This effect was first described scientifically by Osborne Reynolds in 1885/1886 and is also known as Reynolds dilatancy. Unlike most other solid materials, the tendency of a compacted
Wivenhoe Gravel Pit Wivenhoe Gravel Pit Wivenhoe Gravel Pit is a 2.1 hectare geological Site of Special Scientific Interest north of Wivenhoe in Essex. It is a Geological Conservation Review site. The site is the type locality for the Wivenhoe Gravel, which was laid down by the River Thames before it was diverted south to its present course by the Anglian glaciation around 450,000 years ago. The gravel was laid down during two cold stages with an intervening interglacial, but the fossils in from this warmer period are not distinctive enough to identify which interglacial they come from. The site is important for