Gabion Wall

What a gabion wall is

A gabion wall is a gravity retaining wall. It is built from gabion boxes — rectangular cages of double twisted hexagonal wire mesh — stacked in courses, laced to each other, and packed with hard stone. Its own weight resists the push of the earth or water behind it, in the same way a concrete gravity wall does.

The difference is in how it behaves. The mesh lets the wall deform without breaking, so it tolerates settlement and ground movement that would crack concrete. And because it is made of stone with voids between, water passes straight through it instead of building up pressure behind it.

Where gabion walls are used

• Hill road retaining walls on the valley side of a formation
• Breast walls holding up the cut slope on the hill side
• Toe walls at the foot of an embankment or slope
• River bank protection, where the wall faces the current
• Landslide repair and reinstatement of slipped formations
• Bridge approaches, wing walls, and landscaped and boundary walls

The full list, and which unit each job needs, is on the applications page.

Why engineers choose it

• It drains itself. A gabion wall needs no weep holes and no drainage blanket behind it — what it does need is a filter so soil cannot wash into the voids (IRC:SP:116, cl. 6.1).
• It tolerates movement. Soft or settling ground that would crack a rigid wall is absorbed by the mesh.
• It uses local stone. Only the mesh has to be transported; the fill is quarried or collected near the site. On a hill road that is the whole argument.
• It needs no formwork and no curing, so it can be built and loaded as it goes up, with local labour.
• It uses smaller stone than loose protection would. The cage lets stone that would be too small to stay put on its own act as one heavy block.

For a side-by-side comparison, see gabion wall vs RCC retaining wall.

How it is designed

A gabion wall is designed like any gravity wall — checked for sliding, overturning, bearing pressure and overall stability. The Indian guideline, IRC:SP:116-2018, gives starting proportions for a first trial section:

• Base width about 0.6–0.75 × the wall height for walls up to 6 m
• Embedded at least 0.5 m into firm ground (more on scour-prone or swelling soils)
• Face battered back 3°–6° from vertical, or stepped

These are for planning and for checking a drawing, not a design. The full set, with the checks the engineer runs, is in the gabion wall design guide.

What it is made from

• Gabion boxes in 8×10 or 10×12 double twisted mesh, commonly 1.5–4 m long, 1 m wide and 0.5 or 1 m high, with a diaphragm every metre — specification
• Wire — mesh, selvedge and lacing wire, galvanized or PVC coated — gabion wire explained
• Stone fill — hard, durable, sized to the mesh — choosing gabion stone
• A geotextile filter between the wall and the backfill

Building one

Assembly, lacing, filling in layers with internal tie wires, and keeping the face true are covered step by step in how to build a gabion wall. For budgeting, see gabion wall cost.

Questions