Geogrid products, which are polymeric in nature, are utilized for reinforcing soil in a variety of different geotechnical projects such as soil stabilization embankments, landfill projects and much more. Two products commonly used are uniaxial geogrids and biaxial geogrids. Although the two types of geogrids share a number of features in common that make them similar, in practical use they are radically different. Here’s how to know them apart.
Geogrids 101
Before we get into Uniaxial Vs Biaxial Geogrids, let’s start with a basic understanding of what a geogrid actually is. Geogrids are polymer materials, (usually of polypropylene PP or polyester) that are utilised to assist in reinforcing soils. Other applications also include road construction, the reinforcing of landfills etc.
Simply put, geogrids will give a tensile reinforce to “heavy” soils or dirt, holding it together properly while preventing lateral deformation of that soil.
Uniaxial Geogrid
The Uniaxial Geogrids or the Monodirectional Geogrids are manufactured grids (PVC) that perform essentially in one direction only. That is, that the strands in a Uniaxial Geogrid only lie in a single direction. These geogrids are great for Soil or structures that are going to receive a “predominant” force in a given direction. •Slope Stabilisation: Their strength in one direction means they are great for steep slope reinforcement or other such uses to prevent slip and soil erosion.Uniaxial Geogrid
Used in soil reinforcement of a retaining wall where most of the force is acting in one direction because of the weight and pressure of the earth being held.
Benefits of Uniaxial Geogrid
Strong in one Direction: The Uniaxial geogrid can resist a higher load in one direction, useful for reinforcement where we can read the forces.
Lower Cost: Using every seond product, a Uniaxial geogrid is often cheaper than the same product as a Biaxial.
Simple to Install: The force of the movement is acting in one “vector” of its direction so it’s a simple install.
Disadvantages of Uniaxial Geogrid
The needs of some soil movement means the product should be available in more than one direction, where the movement is multi-directional this is often only effective to a limit.
Biaxial Geogrid
In contrast to teh Uniaxial geogrid would be the Biaxial Geogird grid, commonly used for reinforcement that requires the ‘grid’ to be strong in more than one direction. The strands of polymer in the grid are laid in two perpendicular directions, strands in both the longitudinal and crossApplications of Biaxial Geogrids: Roads and Pavements: Biaxial geogrids are often used in road construction, as they provide reinforcement in both directions, improving the load distribution and reducing the likelihood of pavement failure.Landfill Reinforcement: Their two-directional strength makes them perfect for reinforcing the base and slopes of landfills and give an additional strength to prevent movement.
Subgrade Stabilization: Biaxial geosynthetics are often used for subgrade stabilization, especially as they ‘spread the weights’ made upon it over the entire surface.
Benefits of Biaxial Geogrids:
Better Load Distribution: Because they offer the load across two directions they are better for distributing the load.
Good Use: Biaxial geogrids are good ‘all rounders’ and thus can be useful in all sorts of areas.
Soil Reinforcement: The way they sit on soil help with their confines & tensile support. Good for subgrade stabilization and other multi-direction applications as well.
Drawbacks of Biaxial Geogrids:
More Expensive: Generally, biaxial products are more expensive due to two directional strengths and the method used to make them.
Less specific applications: Because they operate in two directions like that, they can be less efficient with certain projects where one/straight might be adequate.
What sets Uniaxial and Biaxial Apart
Telling u from other types of geogrids gets down to where the strength is. Some products are really meant for certain conditions, where reliance on strength is one way, provided by the geosynthetic. Others offer the strength at two directions and are often rather more complex, having greater costs and use see the Table.
FeatureUniaxialBiaxialReinforcementOne directionTwo perpendicular ratiosCostGenerally affordableHigher due to complex designApplicationsEmbankment, retaining walls, slopesRoads, pavements, etc.DistributionMainly in One DirectionEvenly in 2 DirectionsInstallationEasier & quickerMay be more complexStrengthGreat in One DirectionStronger in multi direction projects & applicationsHow can You Choose Which?
It comes down to what you are asking the geogrid to do where, and how, to put it. With one direction of load or force that soil construction relies upon, the uniaxial would be the choice. However when things are more complex…road and pavement reinforcement, application of certain materials in landfil fields for instance, an altogether different system seems indicated to aid a satisfactory and, of course safe, result.