Geogrids

Geogrids are geosynthetic reinforcement products consisting of a grid-like network of ribs forming apertures. They are used to reinforce soils and granular materials by distributing loads over a wider area and improving stability.

Two main categories exist: polymeric geogrids made by extrusion or weaving from materials such as polypropylene, high-density polyethylene, or polyester; and steel geogrids made from stainless or galvanized steel strips. Polymer geogrids are generally corrosion resistant and lightweight, while steel geogrids offer very high strength but require protection from corrosion.

Geogrids work by interlocking with the surrounding soil or aggregate in the filled layers, creating a composite mass that resists deformation. Lateral confinement and load transfer along grid blades increase bearing capacity, reduce settlement, and stabilize slopes and embankments. The aperture size and grid stiffness influence the interaction with particles and affect drainage characteristics.

Common applications include road and highway embankments, railway ballast reinforcement, retaining walls, foundation support, slope stabilization, and load-bearing surfaces such as parking areas or landfill covers. Selection typically considers tensile strength, stiffness, and aperture size relative to the soil or aggregate being reinforced.

Installation and design considerations emphasize placing the geogrid between lifts of fill with correct orientation, avoiding folds or wrinkles, and ensuring full coverage. Polymer geogrids are generally more UV-sensitive and may require protection or burial, while steel geogrids require corrosion protection and compatible coatings.

Geogrids are governed by international standards and testing methods for tensile strength, stiffness, and mesh integrity, and proper installation practices, including attention to drainage and filtration, are essential to performance.