Geogrid is a synthetic material made of polyester, polyethylene, or polypropylene resembling a large grid used in subgrade stabilization measures. Geogrid is categorized by manufacturing method:
- ‘punched and drawn’
A sheet of either HDPE or Polypropylene has holes punched into it in a regular pattern and the sheet is then ‘drawn’ or ‘stretched’ into the finished product.
- coated yarn
In the form of grids which use bundles of fibers (most commonly Polyester) as the reinforcing component. The grid is coated to provide protection during installation and service. The grid structure is formed by knitting or intertwining the transverse and longitudinal bundles of fibers.
- laser welded (3 shapes)
Uniaxial (Slopes and wall applications)
BiAxial (Roads and other pavements)
The primary purpose of utilizing geogrid is to increase the bearing capacity of a subgrade by spreading loads over a wider area. Geogrid also assists in slope stabilization. It is typically used in areas with a weak or soft subgrade, where undercutting and replacement of existing subgrade material is too costly or otherwise undesirable. It is common for the Geogrid manufacturer to require that heavy equipment not be operated directly on the geogrid before it has been covered with aggregate stone.
Some characteristics of geogrids of which an engineer may select or specify a geogrid are:
-rib thickness height
-open area percentage