Geogrid for Retaining Walls
If you’re building a retaining wall, it’s important to consider using geogrid to stabilize the soil. This prevents unwanted soil movement, reducing stress on the wall.
Stabilizing grid is made from a strong woven material of high tensile strength, which is pinned between layers of the retaining wall. It recruits the retained soils as helpers in retention, lowering bearing pressures and enabling larger walls to be built.
Strength
If you want to build a strong retaining wall, geogrid is the way to go. It adds strength to your wall by interlocking with soil, increasing its mass and stability. This is how it resists lateral pressures and movements that occur behind the retaining wall. Geogrid also enhances the appearance of your finished retaining wall by making it appear more natural and less industrial.
Once you’ve removed 8’ or more of subsoil and graded the rest of the slope, lay a foot of free-draining granular material horizontally adjacent to the wall on the uphill side. Then backfill with the first row of masonry blocks. After laying the first row, cover with the perforated weeping tile or crushed rock. Then, place a layer of VERSA-Grid over the backfill and grading base. Roll the grid perpendicular to the wall, and make sure it covers all holes and slots in the VERSA-LOK units. Make sure the length of the geogrid is dictated by a certified engineer and based on your wall height and the conditions of the soil and subgrade.
Uniaxial geogrids are ideal for slope reinforcement and retaining walls. They have rectangular apertures and offer high tensile resistance in one direction. They’re more affordable than biaxial geogrids and can be used for many types of applications. However, they aren’t appropriate for roadways or other areas that require high-strength materials because of their limited tensile strength.
Durability
The durability of geogrid helps retaining walls last longer and provides more stability for the soil behind them. This allows builders to build much taller walls using less material than they geogrid for retaining walls would be able to with conventional gravity walls alone. It also reduces the cost of construction by allowing the use of cheaper, locally sourced fill materials.
Once the excavation has been completed and a leveling pad has been built, it is time to start putting in the geogrid. Begin by cutting sections from the roll to the correct length for embedment in the wall. The length should be equal to the height of the block, plus the maximum embedment depth. This is important to ensure the geogrid can withstand the load of the soil.
Biaxial and uniaxial geogrids are available in a variety of sizes and strengths commonly used for landscape and commercial walls. Both can be laid in a similar way, but it is recommended that the uniaxial geogrid be positioned so the thick or stiff strands are perpendicular to the wall and going into the blocks. Once pinned in place, the next course of masonry can be placed and tamped down over the grid.
To understand how geogrid works, imagine holding a clump of compacted soil in your hand. When you press down on it, the soil will lose its shape and may either spread out or crumble away. Geogrids prevent this by preventing the soil from moving beyond its confines, creating a stable base.
Flexibility
Adding geogrid soil reinforcement to a retaining wall helps to reduce its stress and movement. It does this by spreading concentrated loads over a larger area. This also increases the load-bearing capacity of soft sub-soil. This can help to reduce the cost of retaining walls by eliminating the need for footings. It can also increase the longevity of a wall by reducing maintenance needs.
Geogrid is a tough, durable woven fabric that is pinned between layers of retaining wall. It can be made from different materials and has a variety of sizes. It is also easy to cut and can be trimmed to fit the specific site conditions. It is an excellent option for building a retaining wall, especially in sloped areas.
During installation, it is important to lay the grid in accordance with the manufacturer’s guidelines and to check for correct orientation (biaxial or uniaxial). The right orientation is crucial to achieving unified strength and proper coverage of holes and slots in VERSA-LOK units. Once in place, Uniaxial Plastic Geogrid it is important to hand-tension the grid. This will help to ensure that it is taught and there is no slack.
When paired with the proper soils, geogrid can significantly increase the stability of a retaining wall. It spreads lateral forces and surcharge loads over a wider range, which can greatly decrease settlement. It can also be used to improve the load-bearing capability of soft soils and allow the construction of taller retaining walls.
Cost
While the cost of geogrid varies from project to project, it is an investment that can reduce your overall retaining wall construction costs. Geogrid adds strength to the soil, allowing for less costly backfill materials and increasing the load-bearing capacity of soft soils. It also allows you to reuse poor quality in-situ soil, which would otherwise be difficult to construct a retaining wall with.
The first step in building a retaining wall with geogrid is to excavate the organic soil, build a leveling pad and lay a base of compacted gravel. Once these steps are complete, you can then place your first block layer. Next, lay a sheet of uniaxial geogrid over the base of the wall. This type of geogrid distributes point loads evenly, preventing movements towards the blocks. If your project requires more stability, use triaxial geogrid to distribute the pressure from different directions.
Once the geogrid is in place, place the next block layer and then tamp down the fill to create a smooth, solid surface. You can then install a geotextile fabric, drain pipes and more as per your design. This process is repeated for every other block layer until your final retaining wall is finished. If you’re using a biaxial geogrid, such as VERSA-Grid, it is strongest along the roll direction and should be laid perpendicular to your wall.
