Gabion Wall Design

How a gabion wall works

A gabion retaining wall is a mass gravity wall: its own weight — wire mesh boxes packed with stone — resists the push of the soil behind it. It has three working parts: the gabion boxes (usually 1 m or 0.5 m high units, laced together), the stone fill, and a filter and compacted backfill behind the wall.

Because the units are flexible and free-draining, a gabion wall tolerates settlement without cracking and does not build up water pressure behind it. Those two properties are why gabion walls are chosen for hill roads, river banks and soft or uneven ground.

Base width

The base must be wide enough for the wall to resist sliding and overturning. As a starting point, IRC:SP:116-2018 suggests:

The final width comes from the stability calculation, not from the ratio alone.

Embedment, batter and steps

• Embedment: set the base at least 0.5 m below ground for walls up to 6 m, and 1 m for taller walls — more where scour, soft or swelling soils or frost apply. On rock it can be reduced, with the foundation levelled.
• Batter: lean the wall back into the soil by about 3–6° from vertical, or build it with vertical units stepped back on the outside face.
• Steps: the width usually reduces up the wall, course by course, which saves material while keeping the weight low down where it is needed.

Stone fill

• Hard, durable stone that will not break down in water or weather.
• Size about 1.5–2.5 times the mesh opening, so no stone can pass through the mesh.
• Hand-packed with the larger face horizontal; at least three layers of stone in a 1 m unit and two in a 0.5 m unit.
• Well-packed gabions have about 35–40% voids; small stones placed in the gaps keep this down.

Backfill, filter and drainage

Place a filter layer between the gabions and the retained soil so fine soil cannot wash out through the stone. Use selected, free-draining backfill and raise it and compact it together with the wall, course by course — not after the wall is finished.

What the engineer checks

A gabion wall is checked like any gravity wall: sliding, overturning, bearing pressure on the foundation, internal stability between courses and overall (global) stability of the slope. Loads include soil pressure, traffic surcharge on top and, in seismic zones, earthquake forces.

Specifying the gabions

Tender items are normally written “as per IS 16014 and MORTH Specification Clause 2500”, stating the mesh type (for example 10×12), coating (galvanized or PVC coated), mesh, selvedge and lacing wire diameters, and unit sizes. See the gabion box specification for the standard wire schedule.

Questions