Types of Retaining Walls
The following are five of the most common types of retaining walls used in the construction industry:
- Gravity Walls
- Cantilever Retaining Walls
- Sheet Pile Retaining Walls
- Anchored Retaining Walls
- Counterfort Retaining Walls
Retaining Walls: Gravity Walls
Gravity walls are used when the height of the wall will not exceed more than 8 feet. This type of retaining wall uses its own weight to resist pressure acting upon it. Gravity walls are designed in such way that its base is wider and thicker than the top of the wall. They are built leaning backwards adding weight or 'pushing' backwards thus the importance of having an appropriate drainage mechanism behind the retaining wall. These type of retaining wall is also used when there is enough space to build its footing, because it can usually be at least half to three fourths wide of its height. This structure as we have indicated before has certain height restrictions and will not be effective holding taller slopes.
Retaining Walls: Cantilever Walls
Cantilever walls are ideal for holding tall slopes as they are built using single-layered walls built in uniform thickness with its base connected to a slab. These walls need to be designed by a structural engineering following geotech recommendations as it requires certain degree of complexity when designing. These walls will require lots of steel reinforcement at its base and surface, in order to support all loads acting on the retaining wall.
Retaining Walls: Sheet Pile Retaining Walls
Sheet pile retaining walls are normally used on soft soils. Sheet pile walls are built by driving or vibrating prefabricated steel sections into the ground. Those steel sections are connected in sequential installations to form the retaining wall structure. Sheet pile walls are ideal where deep excavations are required although reinforced concrete might be used too. When taller sheet pile walls are required, a tieback can be installed to keep the wall in place, and a cable will bond the wall and the tieback together.
Retaining Walls: Anchored Retaining Walls
Anchored retaining walls are very similar steel pile retaining walls, although they require a cable for added strength. These cables are installed into the material and then expanded by mechanical methods or by using concrete that holds up the cable. These cables in conjunction with the wall will resist the pressure exerted on the wall. It is an extremely useful retaining wall when heavy loads are acting on the wall.
Retaining Walls: Counterfort Retaining Walls
Counterfort retaining walls are similar to cantilever walls, except that they have vertical concrete webs along the backside of the retaining wall. These webs known as counterforts, connect the wall's top to the base, reducing pressure in the wall. Counterfort retaining walls are more preferable and economical to use than cantilever walls when building structures of heights 25 feet and above. These walls can be precast or formed-in-site and they will also help to increase the weight of the wall from the added concrete.