Retaining wall design


Retaining wall design principles

Retaining wall design – Retaining walls can fail in many ways. The diagram above and the explanation below describes the failure types.

Overturning – The material being retained creates a force (moment) that causes the toppling of the wall.  The weight of a gravity retaining wall resists this moment.

Bearing capacity – The weight of the wall and earth is supported by the ground beneath. The ground bearing capacity needs to be checked to ensure any settlement is within limits.

Sliding – The retaining earth creates a horizontal force that can cause the retaining wall to slide. This is resisted by the friction between the wall and the earth beneath, and the embedment of the wall.

Stability – The earth around the wall requires adequate strength to avoid an overall slip failure.

Shear – The blocks can shear at the base or on courses. We introduce a kicker at the base and interlocking buttons to resist these forces.

Retaining wall design

Now we know how retaining walls fail we can design them so they don’t fail. The types of retaining walls we build use interlocking concrete blocks. They deliver a fast and economical solution to many civil engineering retaining wall problems. The types we design and build are:

Gravity retaining walls : Use the mass of the blocks to resist the forces

Reinforced block retaining walls : Use the reinforced block wall together with the foundation to act as a cantilever to resist the forces

Inclined retaining walls  : Use the mass and gravity acting on the inclined blocks to resist the forces

Reinforced earth retaining walls : Use the reinforced earth as the retaining structure

The concrete interlocking blocks come in three sizes 300, 600 and 800mm wide. The blocks interlock so they cannot slide from the horizontal joints. The walls are designed to resist the failure modes above. A soil investigation has to be carried out to check the ground bearing capacity and to make sure the wall is stable within the ground. We highly recommend that a structural engineer reviews all design to make sure they work. We can do this work for you using our structural engineering service.

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Retaining wall design guide

Download our free design and price guide to learn how to design and build fast and economical retaining walls. The guide is essential reading for civil engineering contractors, self-builders and structural engineers. It will give you some great design ideas for your project.