Loosesand

Loosesand, often written as loose sand, refers to sand in a loose, unconsolidated state in which individual grains can move past one another. It is defined by grain sizes typically between 0.0625 millimeters and 2 millimeters, with relatively low cohesion and high porosity. The porosity of loose sand commonly ranges around 0.3 to 0.5, and its permeability is high, allowing fluids to pass through easily.

Loose sand forms through deposition and weathering in environments such as beaches, dunes, deserts, and riverbanks. Wind and water sorting commonly produce layers of uniform grains, while moisture and mineral cementation can gradually alter its properties. In natural settings it supports various ecosystems and can migrate under wind or water forces, forming features like dunes or sand sheets.

Engineering and environmental behavior: Because it is unconsolidated, loose sand has relatively low shear strength in its natural state and can compact under loading. Densification increases strength and reduces settlement. When saturated, loose sand can liquefy during earthquakes, leading to ground failure and instability. It is also susceptible to wind erosion, dust transport, and dune migration, which can affect infrastructure and land use.

Uses and management: Loose sand serves as a natural medium for ecosystems and, when properly compacted and stabilized, can function as a construction fill. It is used in filtration, artisanal and industrial applications, and as a source material for glassmaking in suitable deposits. In geotechnical practice, loose sand is compacted or stabilized with moisture, binders, or other methods to achieve desired strength and reduce erosion or settlement. Related topics include dunes, sedimentology, and soil mechanics.