Types of Retaining Walls

Retaining walls are structures designed to restrain soil to unnatural slopes. They are used to bound soils between two different elevations often in areas of terrain possessing undesirable slopes or in areas where the landscape needs to be shaped severely and engineered for more specific purposes like hillside farming or roadway overpasses.

Cantilever Retaining Walls:-

Cantilever retaining walls are constructed of reinforced concrete. They consist of a relatively thin stem and a base slab. The base is also divided into two parts, the heel and toe. The heel is the part of the base under the backfill. The toe is the other part of the base.

Use much less concrete than monolithic gravity walls, but require more design and careful construction.
Generally economical up to about 25 ft. in height.
Can be precast in a factory or formed on site.

Counterfort Retaining Walls:-

Counterfort retaining walls are similar to cantilever walls except they have thin vertical concrete webs at regular intervals along the backside of the wall. These webs are known as counterforts.

The counterforts tie the slab and base together, and the purpose of them is to reduce the shear forces and bending moments imposed on the wall by the soil. A secondary effect is to increase the weight of the wall from the added concrete.
Can be precast or formed on site.
Counterfort retaining walls are more economical than cantilever walls for heights above 25 ft.

Gravity Poured Concrete Retaining Walls:-

Gravity retaining walls depend on their own weight and any soil resting on the concrete in resisting lateral earth forces.
They are generally economical up to 10 feet in height for cast concrete structures.
Usually are sufficiently massive to be unreinforced.
Monolithic cast walls are generally formed on site.

Semi-Gravity Retaining Walls:-

A specialized form of gravity walls is a semi-gravity retaining wall. These have some tension reinforcing steel included so as to minimize the thickness of the wall without requiring extensive reinforcement. They are a blend of the gravity wall and the cantilever wall designs.

Anchored Retaining Walls:-
An anchored retaining wall 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. Usually driven into the material with boring, anchors are then expanded at the end of the cable, either by mechanical means or often by injecting pressurized concrete, which expands to form a bulb in the soil. Technically complex, this method is very useful where high loads are expected, or where the wall itself has to be slender and would otherwise be too weak.