Retaining walls are essential to many properties when the land is sloped, steep, or tiered. Any structural weakness, or inability to manage the load upon it, may lead to not only the collapse of the wall over time, but to potentially expensive, and even life-threatening, consequences.
Types of Materials Used
While retaining walls have, in the past, consisted of natural materials like rocks and timber, today’s are increasingly using man-made materials like steel. This is for many reasons, not the least of which is strength and longevity.
The Problems Associated with Wood and Concrete Retaining Walls
Timber, even treated pine, is prone to degradation over time. Red gum, more traditionally used for retaining walls due to its rustic charm, is particularly prone to rotting, not to mention termites.
Naturally, any degradation reduces the structural integrity of the wall. Both timber and concrete are also very heavy, sometimes requiring specialist vehicles to transport them to the site.
Earth Pressure
Regardless of the type of material used in a retaining wall, they have many loads and forces acting on them, lateral earth pressure being the main load. This may vary depending on the nature of the wall.
- Walls that are fully vertical are subjected to at-rest earth pressure.
- Walls that tilt away from the retained soil are subjected to active earth pressure.
- And walls that are pushed into the soil the wall retains experience passive earth pressure.
For a retaining wall to be structurally secure, each of these lateral earth pressures needs to be calculated and the wall built so that it can withstand the pressure, including when the soil is water-logged after heavy rain, or when heavy items are placed on top of the ground behind the retaining wall.
Properly Engineered
Given the safety consequences of inappropriately designed and engineered retaining walls, you must have your wall engineered by a qualified professional who doesn’t cut corners.
Using retaining wall sleepers that have both strength and longevity will aid with structural integrity and lead to cost savings in the long run.
