Retaining wall

A retaining wall is designed to hold in place a mass of earth or the like, such as the edge of a terrace or excavation.

Lateral earth pressures are zero at the top of the wall and – in homogeneous ground – increase proportionally to a maximum value at the lowest depth.

The total pressure or thrust may be assumed to act at one-third from the lowest depth for lengthwise stretches of uniform height.

[6] 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.

They can be built to a low height without additional materials being inserted, and have concrete added for strength and stability.

[9] 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).

Sometimes cantilevered walls are buttressed on the front, or include a counterfort on the back, to improve their strength resisting high loads.

Sheet pile walls are driven into the ground and are composed of a variety of material including steel, vinyl, aluminum, fiberglass or wood planks.

A rigid or flexible facing (often sprayed concrete) or isolated soil nail heads may be used at the surface.

This type of soil strengthening, often also used without an outside wall, consists of wire mesh "boxes", which are filled with roughly cut stone or other material.

Gabion walls are free-draining retaining structures and as such are often built in locations where ground water is present.

Mechanically stabilized earth, also called MSE, is soil constructed with artificial reinforcing via layered horizontal mats (geosynthetics) fixed at their ends.

These mats provide added internal shear resistance beyond that of simple gravity wall structures.

Cellular confinement systems (geocells) are also used for steep earth stabilization in gravity and reinforced retaining walls with geogrids.