Retaining walls provide useful spaces as they make available flat surfaces where previously the land sloped. These areas can be used for building extensions, outdoor living areas or to increase useful garden space.
The retaining wall design must offer enough support to hold tons of rock and soil in place. It is the wall that prevents the retained weight from collapsing.
The retaining wall design must be such that it can offer lateral support to the soil at different levels on either side of the wall. These walls are often used for huge structures like roadway crossings, dams, and railway bridges.
The primary purpose of the retaining wall design is to provide lateral strength to prevent the retained soil from returning to its previous sloped position.
The lateral pressure of the retained soil will increase at deeper levels. If the drainage isn’t adequate, water will gather behind the wall and build up hydrostatic pressure.
This could exert enough lateral force to push the wall forward or even topple it. The retaining wall design and drainage are therefore vitally important.
The Most Commonly Used Retaining Wall Designs
Properly designed, retaining walls should last almost indefinitely. Over the years, engineers have created a wide range of retaining wall designs. These include;
- Gravity retaining walls – depend on their mass to hold back the retained weight. They often contain reinforcing bars to increase their strength
- Cantilever retaining walls – these are the most common retaining walls. They have a foundation and they also contain reinforcing bars. The heel of the wall extends into the backfill behind it. The weight of the soil provides lateral strength. This is the type of retaining wall design that we recommend for most applications.
- Counterfort retaining walls – are used for tall walls with heights of over 30 feet. Counterforts are spaced at equal distances on the backfill side of the wall. They connect the heel to the stem of the retaining wall to prevent bending stresses.
- Buttressed retaining walls – similar to counterfort walls, buttressed walls have buttresses to give the wall more strength. These are on the opposing wall. The heel slab works in the same way as a cantilever.
Learn more about Xpress Engineering’s affordable Engineering Retaining Wall Designs or Request a Retaining Wall Design for your own project.