Geogrid: Do I need it for my Retaining Wall?

GeoGrid what is it ?

Geogrid is a geosynthetic material used to reinforce soils and similar materials. Geogrids are commonly used to reinforce retaining walls, sub-bases or sub soils below roads or structures. Soils pull apart under tension. Compared to soil, geogrids are stronger in tension. This fact allows them to transfer forces to a larger area of soil than would otherwise be the case.

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You may have to cut the geogrid at different widths depending on the plans'

When the weight of a retaining wall units along is not enough to retain soil loads geogrid will provide the additional soil reinforcement necessary for your wall stability.  A properly design wall can be constructed to heights exceeding 30-40 feet.

 

That's still a little too technical so here it is'.

It's safe to say pretty much any retaining wall over 4 feet or with special requirements might need geogrid (Check with your local building department or engineer).

At All Access, we try to keep it as simple as possible. Remember any of our retaining walls can be built using Keystone, Baselite, Allen block, Belgard, Redi-rock block system, Versa-Lok, or any other system you may think of.

How To Build A Retaining Wall With Geogrid

So you want to build a retaining wall and you're researching geogrid? That's good, because geogrid is a fantastic tool that will make your retaining wall much more robust. This article focuses on small block retaining walls typical of DIY residential retaining wall projects that a lot of homeowners build. These blocks don't require equipment to move and can be hand placed.

There are two main types of retaining wall ' gravity retaining walls and reinforced retaining walls.

A gravity retaining wall is a retaining wall that relies solely on the mass of the retaining wall blocks to hold back the retained soil. Quite rare for small block retaining walls ' only the shortest of walls should be built as a gravity wall when using small blocks.

'Gravity' Retaining Wall Example Design Cross Section

In this article we will be focusing on reinforced retaining walls. A reinforced retaining wall is a retaining wall that relies on both the mass of the retaining wall blocks and the geogrid that is installed behind them. If you're not sure what geogrid is or how it works (in a retaining wall or otherwise), check out this article to brush up.

'Reinforced' Retaining Wall Example Design Cross Section

Reinforced small block retaining walls can be engineered to be very robust ' geogrid is extremely important to the strength of reinforced retaining walls!

 

When Should I Use Geogrid In A Retaining Wall?

The best person to answer this is a geotechnical engineer familiar with the many different site conditions that might be present on your property. While this isn't exactly helpful if you're looking to DIY ' don't worry. We'll still give you some guidance in this article.

Depending on where you live, your governing body will have rules regarding retaining wall heights and the maximum height you can build without having an engineer involved. In Calgary, any retaining wall over 1.2 m needs to be designed by an engineer.

If you're not sure what the rules are where you live you can find out by calling your local permitting office or by calling a local geotechnical engineer or retaining wall builder. Once you've got them on the line, briefly explain your project to them and let them know the maximum wall height you're planning on building. At Factor, we are happy to help homeowners and DIYers over the for questions like this (free of charge of course!)

If your wall is taller than the maximum allowed height, you'll either need to hire an engineer, or you'll need to change up your plans.

Since your wall is short enough that you don't need an engineer you can use a rough rule of thumb for geogrid length in your wall.

Geogrid Length = 0.8 x Retaining Wall Height

So if your wall is 5 feet tall you'll want 4 foot long geogrid layers. For small block walls, geogrid is typically installed every second block layer, starting from the top of the bottom block.

Just be aware that different types of blocks have different requirements and the recommendations given here may not be applicable to every situation and block type. You should check with the block manufacturer's recommendations for geogrid lengths.

 

Drainage

I know this article is about geogrid, which doesn't really have anything to do with drainage' but your geogrid layers are going to interfere with your drainage blanket.. and installing the drainage blanket is a total pain with geogrid.

In case you don't know what a drainage blanket is ' it is a 300 mm (1') thick layer of washed gravel completely wrapped in geotextile filter fabric installed directly behind your retaining wall blocks. The drainage blanket is very important for the performance of your wall ' it prevents the build up of excess water pressure caused by rain, groundwater, snowmelt, irrigation, etc. Excess water pressure on your wall can cause a whole bunch of problems, including complete failure.

In this image (same as the one at the start of this article), you can see the individually wrapped sections of drainage blanket being intersected by the geogrid layers.

Drainage Blanket Sections Individually Wrapped at Geogrid Intersections

 

How Do I Install Geogrid In A Retaining Wall?

Assuming you have completed the very important first steps to building a retaining wall (excavated organic materials under the wall alignment and built a smooth, compacted gravel levelling pad), you are ready to place your first layer of blocks.

Making sure your first layer of blocks is level and has been sufficiently backfilled on the front side of the wall (200 mm or 8 inches is usually good for walls under 1.2 m) you can begin the installation as follows:

For more information, please visit Shuangcheng New Material.

Additional reading:
Buying copper piping (profit question)

Build your first section of drainage blanket

Place backfill behind the wall to the height of the first block and to at least the length of the geogrid you will install
Geogrid Length = 0.8 x Retaining Wall Height

Once the backfill is sufficiently compacted and is the same height as the first block layer, lay the geogrid on the first block layer

The edge of the geogrid on the lower block should be placed as far forward on the lower block as possible without sticking out of the face of the wall (you shouldn't be able to see it once you've built the wall).

If you've bought biaxial geogrid (a.k.a two way geogrid), you can just roll it out along the length of the wall, assuming the roll width is wide enough to satisfy the Geogrid Length equation.

If you've bought uniaxial geogrid (a.k.a one way geogrid) you will have to cut it to the length you need and lay it so that the thick or stiff strands in the geogrid are perpendicular to the wall (going into the blocks).

Once you've covered the entire first block layer with geogrid of the correct length, you can now place the second block layer to pin the grid in place.

With the grid pinned in place by the second row of blocks, carefully begin building your next drainage blanker completely wrapped in geotextile and adding backfill on top of the grid, making sure that the grid stays tight

Compact the backfill in place

Add the third row of blocks

Place backfill and compact in place to the height of block row 3

Place geogrid on the third row of blocks the same as you did in Step 1/2/3

Continue until you've reached your wall height, remembering to compact every backfill layer, building your drainage blanket, and placing geogrid on every second layer

 

 

What Is Geo-Grid Ground Reinforcement

You may have wondered what's under those grass parking lots or gravel driveways that holds everything in place. What you're asking is, 'What is a geo-grid ground reinforcement?' A geogrid is a polyethylene or other synthetic system of apertures (holes) connected with transverse and longitudinal ribs. Geogrids provide reinforcement to load-bearing soils under roads and driveways. They can also prevent erosion on slopes and retain gravel and turf in driveways.

Geo-grid ground reinforcement works by allowing 'soil strike-through' that causes the ground to press against the ribs of the grid, which in turn press against the joints or 'nodes' that connect the ribs to each other. This creates a composite effect as the materials interlock with each other. This behavior distributes loads more evenly across a wide area of soil that otherwise might become rutted or eroded or fail to support the load. Geo-grids have higher tensile strength than the soils they contain and, depending on their size, can endure heavy loads.

There are three types of geo-grids. The original became available in North America in . This version is called 'punched and drawn' because it was formed by punching holes in a sheet of material and then stretching or 'drawing' it into the grid shape.

The second type of geo-grid is a technical textile reinforced by polyester yarns, then coated. The grid is an intertwined or knitted fabric of transverse (sideways) and longitudinal (lengthwise) fibers.

The last type of geogrid is formed by welding or fusing polyester or polypropylene straps or rods, using ultrasonic methods or lasers, to form the grid.

A geogrid's height, the size of its apertures, and the thickness of its ribs all affect its suitability for particular jobs. Civil engineers consider the optimal aperture size, the likely tensile strain, the rib thickness, and the strength of the junctions or nodes where the ribs come together to determine what type of grid to use.

In addition to reinforcing roadbeds and containing gravel, geo-grids are useful supports for retaining walls. They distribute the enormous force of soil pressing against stone or concrete walls to help prevent collapse. Geo-grids also hold railroad beds in place, support logging and coastal roads, and reinforce parking lots.

Vodaland offers three sizes of geo-grid in connectable sections to cover large areas. We also carry geo-grid anchors, plastic manhole covers, and drainage systems for residential and commercial use.

We're commitment to offer you the aggressive cost ,superb products and solutions top quality, too as fast delivery for Geogrid Manufacturer,Geosynthetics Clay Liner (GCL),Stormwater Management,Concrete Protective Liners,Geomembrane Manufacturer,Geotextile Membrane

Choosing the right geotextile fabric for your project can make all the difference in terms of performance and longevity. Whether you need the strength and durability of woven geotextiles or the versatility and filtration capabilities of non-woven geotextiles, EcoGeoX has the perfect solution for you.

At EcoGeoX, we offer a comprehensive range of geogrid products tailored to meet your specific needs. As a leading provider of geocomposite solutions, we ensure the highest quality and performance for your projects.

Ready to make an informed decision? Contact EcoGeoX today and let our experts guide you to the best geogrid for your application. Trust EcoGeoX for reliable, high-quality geocomposite solutions that deliver exceptional results.

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Geogrids are manufactured in two directions, Uni-axial or Bi-axial. Uni-axial grid has one direction of strength and that direction needs to be oriented perpendicularly to the face of the wall during installation. Bi-axial grid can be laid in two directions, perpendicular and lengthwise to the face of wall (ensure that the lengthwise direction is still in accordance to the length specified by the engineer's design).

If you want to learn more, please visit our website Composite Geogrid.