How Geogrids Can Add Strength to Soils and Similar Materials
Imagine holding a clump of soil in your hand and pressing down on it. The soil will lose its shape, either becoming flatter or crumbling.
This is what a geogrid does on a much larger scale. US Fusion’s polypropylene geogrids are strong in tension and offer great tensile strength for reinforcement and stabilization.
Strength
Geogrids are polymeric materials designed to solve civil and geotechnical engineering problems in or on the ground. They have a primary function of reinforcement and can significantly add to the strength and performance of soils and similar materials. Unlike soil, which pulls apart under tension, geogrids are strong in tension and can transmit forces across a much larger area of the material.
They can be made from a variety of polymers including high-density polyethylene and polypropylene. They can be woven from yarns, heat-welded from strips of material or produced by punching a regular pattern of holes in sheets of material which are then stretched into a grid.
The main types of geogrid available are uniaxial and biaxial. Uniaxial geogrids are oriented along the longitudinal or “machine direction” of an extruded sheet of polymer, forming long narrow ribs. Biaxial geogrids are orientated in two directions and form a more complex network of short broad ribs. This more complex geometry increases the tensile strength of biaxial geogrids and allows them to carry higher loads.
When installing a retaining wall, it is important to properly place the Geogrid so that it offers maximum strength and stability. This means laying it perpendicular to the wall in lengths that are dictated by your certified engineer based on the height of the wall and the conditions of the soil and subgrade. It is also important to hand-tension each length of geogrid after it is placed to ensure that it is taught and there is no slack.
Stability
The mechanical properties of geogrids depend on both their geometry and material type. This variety makes it difficult to choose the best product for a specific application. For example, uniaxial and biaxial geogrids differ in their tensile strength and stiffness. Uniaxial geogrids have rectangular apertures and offer high tensile strengths in one direction only, making them ideal for slope reinforcement or wall applications. These include landfill liner systems, embankments over soft soils and steep earthen slopes.
In contrast, biaxial geogrids are suitable for road and pavement construction because they have a strong tensile strength in both directions. They can help reduce the thickness of aggregate layers and prevent ground movements such as settlement or sliding. These benefits can be realised by using geogrids to reduce the Geogrids amount of aggregate needed in a layer, for example, to achieve the same level of performance as a standard mix with lower aggregate content.
Woven and bonded geogrids are made by knitting or heat-welding strips of fabric together. For instance, Wrekin’s CellTrack range is a permanent panelled system that interlocks to create a robust matrix, providing greater stability and reducing the need for gravel. Woven and bonded geogrids also have an increased durability, protecting them against weathering and erosion and extending their lifetime. This helps reduce maintenance costs and extends the life of the project.
Drainage
When you want to add stability geotextile supplier and strength to walls and slopes, geogrids are the best solution. They work with a wide range of fill materials and are easy to install at a shallower depth than traditional soil reinforcement methods. They are also highly durable and resist damage from chemicals, UV exposure, and mechanical damage.
Geogrids are made by extruding a flat sheet of high-molecular-weight polymer material into a grid pattern. A punching pattern is then used to create a series of holes in the geogrid, creating apertures that are bound together by strong, interlocking high-tensile ribs. The ribs can be stretched longitudinally or transversely to develop a high-strength material with excellent shear strength at the junctions, called nodes.
These nodes help the geogrids to resist soil compression, improving the load bearing capacity of the ground. This improves the performance of pavements by reducing environmental cracking and extending their service life.
Apertures in a geogrid allow aggregate to strike through and interlock with it, helping to reduce the movement of soil underneath a road or behind a wall. This helps to prevent concentrated loads from causing structural damage or eroding the base or subgrade.
Environment
Geogrids are a great solution for stabilising and reinforcing soft soil and similar materials that may be prone to settling or erosion. The grid pattern of the stiff but flexible material lends a high tensile strength that helps resist stresses that soil, particularly nutrient-poor or eroded, often cannot.
As a result, they can be used to reduce the structural cross-section of both paved and unpaved roadways without compromising performance. This is a significant cost savings measure. It can also help to extend the life of roads and pavements and reduce annual maintenance budgets.
US Fusion offers a wide range of geosynthetic products including high-quality polypropylene geogrid for stabilisation and reinforcement. If you’re looking to reduce the stress on a bridge subgrade or increase load-bearing capacity in a construction site, contact us today.
Geogrids can be made from polyester, high-density or low-density polypropylenes and are fabricated by knitting or weaving, extrusion, or welding strips of geosynthetics into grids. They have large apertures (also known as ribs) compared to geotextile fabrics, which are typically used in civil engineering applications.
Some studies have investigated the microstructure and environmental behaviors of the primary geogrid products currently on the market. Most reviews have considered only the impact of these properties on specific characteristics such as bearing capacity or soil reinforcement. Few have examined the interactions of multiple factors and effects such as stress state, moisture, and coatings.
