How it Works

Reinforced Earth®


Reinforced Earth® is based on a very simple concept that combines the compressive strength of soil with the high tensile strength of steel reinforcement strips, to produce a composite material that has combined high compression and high tensile strength.

True Reinforced Earth® Bridge AbutmentTerraTrel® Bridge Abutment


Sand and Pine NeedlesReinforced Earth® Principle

The inventor of Reinforced Earth®, French engineer Henri Vidal, discovered this phenomenon in the 1950’s, whilst building sand castles with his family on a beach in the Mediterranean. Having interlaced dry sand with pine needles, not only was he surprised that the castle kept its shape under loading, it’s high strength captured his imagination.


As it so happened, the tensile strength of the pine needles were in fact, preventing the displacement of the sand and stopping it from falling apart. What Henri Vidal went on to prove was “..if reinforcements are judiciously placed in a granular mass, then the whole will behave as a composite mass exhibiting an anisotropic cohesion related to the strength of the reinforcement”.



In a real situation, Reinforced Earth® consists of inextensible steel, or GeoMega® synthetic strips to replace the pine needles. These strips are strategically attached to fascia panels, interlaced between layers of compacted select fill.

Placing Backfill over REhas® reinforcing strips REhas® Reinforcing Strips

Reinforced Earth® Retaining Wall



In observing a Reinforced Earth® structure, it might seem that the fascia panels are doing all the work as with a conventional retaining wall, but this is not so. With Reinforced Earth®, the resulting composite structure supports its own weight with the outer facing intended only to prevent the loss of fill material. In fact, the facing need not be concrete, steel, wire and even timber materials can be used.



Reinforced Earth® structures are far more economical than conventional retaining walls and its natural strength and flexibility make it ideal for absorbing vibrations and dynamic shocks such as those generated from high-speed rail, explosions and earthquakes.

Reinforced Earth® Retaining Wall Reinforced Earth® Structure