Retailing walls are walls designed to for restraining soil to slopes that are not natural. They help to retain soils between two places of uneven elevations. They are made in different places. They are made in places to allow for severe engineering and shaping to serve other purposes like hillside farming. A retaining wall may also be made in regions with undesirable slopes.

These walls come in many types. Common examples are gravity, cantilever, anchored, and piling walls. Their purpose is supporting a wedge of soil. The retained soil tends to shift downslope because of gravitational pull. As such, the design and construction must be done in a way as to counteract this tendency. Gravitational pull results in lateral earth pressure in the supported material. How much pressure is generated varies with the angle of friction and cohesive strength of retained material.

Gravity walls rely on their mass for resistance of pressure exerted on them by pressure behind. Construction is done using stones and concrete to make them heavy. Stability is improved by incorporating batter setback. Sometimes they are made to lean toward the load. Dry-stacked variety is constructed to be flexible and when constructed in regions where frosting occurs, their footings are made rigid.

Most retaining walls constructed during the early years of the 20th century were of the gravity variety. Their construction was done using big masses of concrete and stone. Those that are being constructed in modern times are made of composite materials. Major construction materials include crib walls, soil-nailed walls, and gabions. Construction of gabions is done using stacked steel wire baskets which are filled with rocks.

Cantilevered retaining walls are constructed from an interior stem made from cast-in-place concrete, mortared masonry, or steel-reinforced. Cantilevered walls sometimes get buttressed at the front side. The back may also comprise of a counterfort to enhance the strength of the walls necessary for resisting lofty loads. Buttresses are made in the form of wing walls placed perpendicularly to the main wall trend. These walls need less material to construct compared to gravity walls.

Soft grounds and tight spaces do well with sheet pile retaining walls. The materials used to make these walls are many and diverse and they include steel bars, vinyl, and wood planks. One third of the material protrudes above the ground wile the other two third is driven underground. Theses measurements can be changed as dictated by the situation.

Construction of bored pile walls involves assembling sequences of bored piles. Excess soil on the site of construction is excavated first. Many techniques are employed in the construction process including reinforcing beams, earth anchors, shotcrete reinforcement layer, and soil enhancement operations. Bored pile walls and sheet piling walls can be constructed in the same location. Bored pile walls are preferred if noise and vibration levels are not supposed to be very high.

A lot of evolution has occurred in construction styles. The methods of reinforcing the walls are also many and diversified. Some of the commonly used retention methods employed are cellular confinement, soil-strengthening, soil nailing, and gabion meshes.