What are gabion cages used for?

Cage full of rock

Not to be confused with Bastion

A gabion (from Italian gabbione meaning "big cage"; from Italian gabbia and Latin cavea meaning "cage") is a cage, cylinder or box filled with rocks, concrete, or sometimes sand and soil for use in civil engineering, road building, military applications and landscaping.

For erosion control, caged riprap is used. For dams or in foundation construction, cylindrical metal structures are used. In a military context, earth- or sand-filled gabions are used to protect sappers, infantry, and artillerymen from enemy fire.

Leonardo da Vinci designed a type of gabion called a Corbeille Leonard ("Leonard[o] basket") for the foundations of the San Marco Castle in Milan.[1]

Civil engineering

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The most common civil engineering use of gabions was refined and patented by Gaetano Maccaferri in the late 19th century in Sacerno, Emilia Romagna and used to stabilize shorelines, stream banks or slopes against erosion. Other uses include retaining walls, noise barriers, temporary flood walls, silt filtration from runoff, for small or temporary/permanent dams, river training, or channel lining. They may be used to direct the force of a flow of flood water around a vulnerable structure.

Gabions are also used as fish screens on small streams. Gabion stepped weirs are commonly used for river training and flood control; the stepped design enhances the rate of energy dissipation in the channel, and it is particularly well suited to the construction of gabion stepped weirs.[2]

A gabion wall is a retaining wall made of stacked stone-filled gabions tied together with wire. Gabion walls are usually battered (angled back towards the slope), or stepped back with the slope, rather than stacked vertically.

The life expectancy of gabions depends on the lifespan of the wire, not on the contents of the basket. The structure will fail when the wire fails. Galvanized steel wire is most common, but PVC-coated and stainless steel wire are also used. PVC-coated galvanized gabions have been estimated to survive for 60 years.[3] Some gabion manufacturers guarantee a structural consistency of 50 years.[4]

In the United States, gabion use within streams first began with projects completed from 1957 to 1965 on North River, Virginia, and Zealand River, New Hampshire.[5] More than 150 grade-control structures, bank revetments and channel deflectors were constructed on the two U.S. Forest Service sites. Eventually, a large portion of the in-stream structures failed due to undermining and lack of structural integrity of the baskets. In particular, corrosion and abrasion of wires by bedload movement compromised the structures, which then sagged and collapsed into the channels. Other gabions were toppled into channels as trees grew and enlarged on top of gabion revetments, leveraging them toward the river channels.

Gabions have also been used in building, as in the Dominus Winery in the Napa Valley, California, by architects Herzog & de Meuron, constructed between 1995 and 1997. The exterior is formed by modular wire mesh gabions containing locally quarried stone; this construction allows air movement through the building and creates an environment of moderate temperatures inside.[6][7]

Variations in design

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There are various special designs of gabions to meet particular functional requirements and some special terms for particular forms have come into use. For example:[8]

• Bastion: a gabion lined internally with a membrane, typically of nonwoven geotextile to permit the use of granular soil fill, instead of rock.
• Mattress: a form of gabion short in height relative to the lateral dimensions; commonly very wide. For protecting surfaces from wave erosion and similar attack, rather than building or supporting high structures.[9]
• Trapion: a form of gabion with a trapezoidal cross-section, designed for stacking to give a face that is sloping rather than stepped. The term is in wide usage, but in contexts related to gabions at least, appears to be a trademark registered by Betafence Limited.

Military use

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Early gabions were round cages with open tops and bottoms, made from wickerwork and filled with earth for use as military fortifications.[10]: 38  These early military gabions were most often used to protect sappers and siege artillery gunners.[10]: 39  The wickerwork cylinders were light and could be carried relatively conveniently in the ammunition train, particularly if they were made in several diameters to fit one inside another. At the site of use in the field, they could be stood on end, staked in position, and filled with soil to form an effective wall around the gun, or rapidly construct a bulletproof parapet along a sap. During the Crimean War, local shortages of brushwood led to use of scrap hoop-iron from hay bales in its stead; this in turn led to purpose-built sheet-iron gabions.[10]: 182 

Today, gabions are often used to protect forward operating bases (FOBs) against explosive, fragmentary, indirect fires such as mortar or artillery fire. Examples of areas within a FOB that make extensive use of gabions are sleeping quarters, mess halls, or any place where there would be a large concentration of unprotected soldiers. Gabions are also used for aircraft revetments, blast walls, and similar structures. A gabion is often referred to as a "Hesco bastion".

• The interior of Fort Stedman in 1865, showing a breastwork constructed with gabions to protect gun positions

• Modern Hesco bastions

Impact attenuation

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Gabions may be used for attenuating dynamic load as those resulting from impacts by vehicles or rockfall for example. First, gabions may be suitable as a vehicle restraint system in scenic lower speed roads.[11] Second, when used as facing of earth-reinforced structures with a vertical face, gabions offer a more deformable surface to impact compared to other classical geotechnical alternatives. This higher deformability results from crushing and large displacements of the fill content. As a result, the impact load transmitted to the structure is reduced, due to both impact energy dissipation and peak force attenuation. In an optimization process, the fill material can be adapted to meet specific requirements, in terms of impact response. This in particular led to the use of recycled materials (tires and ballast from railway tracks) in the core of some rockfall protection embankments.[12][13]

See also

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• Cellular confinement – Confinement system used in construction and geotechnical engineering, a small-scale mattress gabion used for roads, retaining walls, and protective structures.
• Hesco bastion – Flood control and military fortification barrier, a modernized version of the same concept
• Maccaferri gabion – Type of rock-filled cage, wire mesh gabions introduced into modern civil engineering
• Stepped spillway – Structure for energy dissipated release of flows from a dam or levee

References

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• Freeman, Gary E.; Fischenich, Craig J.(May 2000), "Gabions for Streambank Erosion Control", Environmental Laboratory, U.S. Army Corps of Engineers.
• University of New South Wales Water Research Laboratory, Research Report No. 156, "Some factors affecting the use of Maccaferri gabions and reno mattresses for coastal revetments", October 1979, C. T. Brown, et al.

Gabion walls were used to protect the banks of the Nile in ancient Egypt over 7,000 years ago, and they’re still used today by civil engineers all around the world as an incredibly effective and efficient retaining wall. Good news for you: they’ll also work just as well in your backyard to protect your landscaping from soil erosion. But what exactly is a gabion wall?

The word “gabion” is taken from the Italian “gabbione,” meaning “big cage”—and that’s exactly what a gabion wall is! It’s an enclosure that holds inorganic materials including stone, brick, concrete pieces, and more in the shape of a sturdy wall. Historically, gabions were made out of wicker cages, but today they’re made of sturdy galvanized steel wire mesh. You can easily purchase premade gabion cages and pack them with whatever fill material you have on hand, and then boom—you’ve got a gabion wall.

Gabion Retaining Walls in Backyard Landscape Design

The Pros of Gabion Walls

• Erosion control: Gabion retaining walls reduce wind and water flow to protect any vulnerable areas of your landscape from damage.

• Easy installation: Building gabions is simple and can be learned quickly. They generally don’t have to be dug into the ground as their own weight holds them down, and they don’t typically require expert design or installation unless your wall height is over 3 feet.

• Affordability: The price for the steel mesh is relatively low and is offset by skipping the cost of the expert mason you would need to lay a comparable traditional stone wall. The real draw here is that you can choose your own fill material, so you get to set your own price and can use low cost or even free materials.

• Eco-friendliness: Choosing your own fill also means you have the option to use recycled materials or use local materials to reduce shipping costs! You can use stone already on your land, leftover backfill materials, repurposed chunks of broken concrete, and more.

• Permeability: Gabion walls are excellent for reducing wind and water flow without stopping it entirely and rerouting that deluge elsewhere. Instead, water is allowed through as a gentle trickle and strong wind can still pass through the fill as a cooling breeze.

• Longevity: Gabions are incredibly long-lasting and only get stronger as they age. As the fill material settles and the gaps are filled with silt, plants, and detritus, the wall simply becomes sturdier. They can rise and fall entirely undamaged as the earth shifts in freeze cycles. The biggest threat to a gabion wall is rust to their steel frame, which is typically only an issue in coastal areas with heavy salt spray.

• Aesthetics: The sleek metal cage of a gabion wall provides very clean, modern lines. You can accentuate that with your fill material or contrast it with rustic stone for an appealing marriage of rustic and modern design styles. Even better, using a local stone offers a way to show off beautiful regional materials.

Photo Credit: Stone Decorative

Gabion Raised Garden Bed @ Wayfair

Gabion Wall Retaining Wall

The Cons of Gabion Walls

• Aesthetics: While many people find the clean lines and industrial edge of gabion walls appealing and invigorating, others find that modern style to be too jarring for their garden. Their unique style has to be matched with the right landscape and the right landscaper.

• Not suitable for small projects: Gabions are bulky, and their rigid frames mean that they’re not easy to bend and shape. They’re wonderful for creating large, bold, straight lines, but not well suited for small spaces or curved walls.

• Possible animal habitats: The nooks and crannies in gabion walls make them an appealing nesting site for all sorts of burrowing critters. That can be a positive if you enjoy sharing your space with local wildlife, but not everyone is looking to invite a new neighbor into their yard.

Gabion wall steps

How to Use Gabion Walls in Landscape Design

Despite their frequent industrial usage, it doesn’t have to be difficult to elegantly incorporate gabion walls into your yard. They’re a natural fit for any modern design style, making them look at home alongside clean lines, sleek concrete, and shiny metal. However, they can also pair nicely with more traditional landscaping styles when filled with natural stone.

They are most typically used for retaining walls, but that’s just the start of their potential. Clever retaining wall design can allow them to perform double duty as erosion control and outdoor benches with the simple addition of poured concrete slabs on top. They can be used to divide a space, surround an outdoor fire or planters, add privacy, or add visual interest with interesting fill materials.

Because gabion wall building materials are so varied, you have many options for the final look of your finished wall. The most stable fill materials are chunky and angular, allowing them to lock together and prevent shifting. With that rule in mind, almost any sturdy material is fair game!

Stone is the most common option, which offers a wide selection of colors, textures, and regional specialties. Recycled construction materials are another favorite—chunks of concrete pulled up from patios, industrial sites, and even roads make for an ideal eco-friendly fill. If you’re less worried about stability and more worried about style, your options open up even further. Designers have filled gabion baskets with rustic wood logs and even colorful glass pieces for a sparkling effect in the sunlight.

Colorado Tilly plan with gabion wall seating

Cost of a Gabion Wall

The first price tag to consider is for the metal gabion cages. They can be custom made for specific projects, but the industry standard for selling pre-fabricated gabion cages is in 3 foot sections. As a rule of thumb, you can estimate a cost of approximately $35 per cubic yard for a typical galvanized stainless steel wire mesh gabion cage.

With that out of the way, it’s time to consider your fill material. The costs here range wildly and are entirely up to you. You may choose to opt for a luxurious imported stone or snag a free truckload of broken concrete that was headed for the dump. Whether you’re a bargain hunter or willing to splurge, you can still end up with a gorgeous new garden wall.

Other costs to consider include possible gravel fill if you need to create a level surface for your cages and consults with a landscape architect or engineer if you’re building a wall that’s load bearing, over 3 feet tall, or structurally significant.

Front Yard Gabion Walls for Decor

Gabion Retaining Walls in an Arizona Landscape Design

Retaining Walls in a Playful New York Backyard

Gabion Wall Seating in a California Backyard Design

Are you ready to dive into building a gabion wall? Their versatility and convenience makes them an ideal choice for a wide variety of landscaping needs and styles. If you’d appreciate some expert advice in planning out your newest landscape addition before you start purchasing wire mesh in bulk, we can help! Our landscape architects are experts in creating functional and beautiful gabion walls that will help bring your landscape to life.