A retaining wall prevents soil from eroding slowly or collapsing suddenly. These walls may be constructed from a variety of materials, including reinforced concrete, timber logs, concrete blocks, brick or stone.

Gravity walls depend on their mass (stone, concrete or other heavy material) to resist pressure from behind and may have a ‘batter’ setback to improve stability by leaning back toward the retained soil.

Cantilevered retaining walls are made from an internal stem of steel-reinforced, cast-in-place concrete or mortared masonry (often in the shape of an inverted T).

Sheet pile retaining walls are usually used in soft soil and tight spaces. Sheet pile walls are made out of steel, vinyl or wood planks which are driven into the ground.

Bored pile retaining walls are built by assembling a sequence of bored piles, proceeded by excavating away the excess soil.

Anchored retaining walls can be constructed in any of the aforementioned styles but also includes additional strength using cables or other stays anchored in the rock or soil behind it.