Interlocking Retaining Wall Blocks
Before we talk about interlocking retaining wall blocks, let me show you how a retaining wall fails. Once we understand the concepts we can use interlocking retaining wall blocks to solve the problem.
The image below shows the failure modes of a block retaining wall:
There are five main failure modes.
Overturning – The material being retained pushed the wall over
Bearing capacity – The earth the wall is sitting on is soft and the wall sinks or slides
Shear – The material being retained slides the wall on the foundation or block course
Sliding – The wall slides on its foundation
Stability – The earth around the wall needs to be stable otherwise the whole area of earth and wall will slide and rotate.
There are a number of ways to build a wall using interlocking retaining wall blocks. They are:
Gravity Retaining Wall – The gravity retaining wall uses its mass to resist the failure modes. The foundation spread the load over a wide area. The mass is greater than the forces that are trying to overturn the wall
Reinforced Block Retaining wall – This wall is a cantilever design and uses the foundation base as part of the structural element of the wall. The wall has reinforcement passing through it, that is connected to the foundation toe. This creates a very effective wall using less blocks than the gravity design.
Inclined block retaining wall – The inclined wall is similar to the gravity wall but uses the incline to give it more gravity force. This design uses less blocks then the traditional gravity wall.
Reinforced earth retaining wall – For high walls and if the soil conditions allow a reinforced earth wall can be very economical. The soil behind the wall is reinforced using geo mat and acts as the retaining structure. The blocks to the front of the wall act as a protective face.
Cost of Construction
We have created a design table for each retaining wall type with a cost index. You can compare the cost of various heights of wall using the tables to work out the most effect solution for your project. Click on the image below you get your copy of our retaining wall design and build guide.