Gabion Standard Design
Below are standard designs. If your situation involves having a building, road etc on top of it then you will need a structural engineer to confirm the design. These are for reference purposes only.
Foundations: Gabions are a mass retaining system so merely need a firm base so the baskets do not sink. A compacted hardcore base is recommended for taller walls.
1m high wall
A 1m high wall is very simple it can be made of 1m x 1m x 1m or 2m x 1m x1m baskets. The smaller is recommended if the length you have to cover is small as it will reduce transport costs. We can also use 1/2m deep baskets this will save on the cost of fill but will reduce the strength of the wall and is recommended only in situations where the bank is fairly stable. You can also use 1m high walls for terracing a garden in steps. We also provide sets of steps for this scenario.
It is standard to use 3mm wire thickness as the baskets have little weight exerted on them.
A cost saving option is to put a false partition in the front of the basket. This way the front can be hand layed with a high quality stone like slate. the back can then be backfilled with a low quality material for example reclaimed brick.
2m high wall
Gabion baskets are a mass retaining system thus, the higher the area that needs retaining, the heavier the wall must be. The standard design for a gabion wall is a pyramid. In general, for every 1m increase in wall height, the bottom row basket depth should be increased by half a meter.
For a 2m high wall the bottom row should be 1.5m deep and the top row should be 1m deep.
It is still standard to use 3mm wire thickness for both rows.
This can be made more stable by setting the top baskets slightly further back.
3m high wall
In this example the top 2 rows are the same as a 2m wall but with a .5m increase in the depth of the bottom row.
The bottom row is 2 meters deep middle row 1.5m deep and top row 1m deep. Normally we use 2m x 1m x 1m baskets bottom row 1.5m x 1m x 1m baskets in the middle row and 1m x 1m x 1m or preferably 2m x 1m x 1m baskets going sideways on the top row.
At this height there is quite a lot of weight exerted on the bottom row and unless the bracing ties are installed correctly there is a possibility that the face of the bottom row might bulge out. You may prefer to use 4mm thick wire on the bottom row rather than risk this. If the look of the wall is important than we would then put a 4mm thick face on the 3mm thick top row baskets. This will save on costs of having all baskets in 4mm.
Any higher than 3m you can still use the same principal of increasing the depth by .5m but it may be preferable to stagger the baskets back and getting a structural engineer to assess the stability of the site would be a preferable option.
Curved wall: Staggered effect using 1m or better .5m wide baskets
There are 2 types of curved walls inside and outside bends. When the wall curves around you when looking at it (inside bend ) this can be achieved easily using standard baskets angled away from each other. The wedge shaped gaps that are left are fixed using extra panels that are cut to size and wired in on site.
Outside curves are more difficult and require the gabion to be tapered inwards. the front panel is larger than the back panel. The baskets require cutting on an angle and welding a new wire on the edges.
We can fabricate many different shapes to fit your project.
Depending on the depth and speed of the river, different designs are appropriate. In general there is a worry that the river will undercut the baskets if using a standard wall. It is normal to use a gabion mattress (a short basket normally 3m x 2m x .3m high) that goes into the stream and underneath a standard wall. The standard wall does the retaining whilst the mattress stops the foundations being eroded.
Gabion Baskets are permeable so that water can come through them, this stops a build up of water behind them and the ground becoming waterlogged. It is possible to stop water coming through by lining the baskets with a thick plastic sheeting. You can have a thin cladding wall basket in front of this so it is not visible. The flood protection offered is only as good as the installation and all joints must be sealed. Care must also be taken to ensure the plastic isn't torn or damaged. Water can still get around the sides of the baskets. This is only suitable in specific location.