How Retaining Walls Work: The Science Behind the Structure
Retaining walls do much more than add structure and style to your garden; they play a huge role in managing soil and preventing erosion. But how exactly do they work? Well, from a mixture of engineering, physics, and smart design.
Retaining walls are built to hold back soil and resist the pressure that builds up behind them. This is especially important on sloped or uneven terrain, where soil movement can cause instability, water pooling, or even damage to nearby buildings or pathways. By providing a sturdy barrier, a retaining wall helps create level surfaces, protect foundations, and improve usable space.
Retaining Walls: The Forces at Play
To understand how retaining walls work, it’s important to look at the forces acting on them.
Soil isn’t just static, it exerts what’s called “lateral earth pressure,” which increases as you go deeper. This pressure pushes against the wall, and the wall must be designed to withstand that force without tipping forward, sliding, or collapsing.
Other factors, like the weight of water (if drainage isn’t managed correctly), the slope of the ground, and nearby loads (like cars or buildings), all add to the total pressure a wall must resist. That’s why retaining walls aren’t just built without thought. They’re carefully engineered with careful planning, solid foundations, and clever use of materials.
Design That Holds Its Ground
There are several types of retaining walls, each working slightly differently.
- Gravity walls, for example, rely on their own weight and mass to hold back soil.
- Reinforced walls, like those built with concrete blocks or poured concrete, may include steel reinforcements and geogrid materials that anchor them into the soil.
- Segmental walls, often used in landscaping, use interlocking blocks and rely on both friction and careful stacking.
Regardless of type, every retaining wall needs a strong base and proper drainage. Water is one of the biggest causes of wall failure, so allowing it to escape (usually via weep holes or gravel backfill) helps reduce pressure and extend the wall’s lifespan.
But, It’s Not Just About Practicality
While the science behind retaining walls is essential, their visual look is, naturally, important too. Whether you’re defining garden beds, creating terraced levels, or adding interest to a flat lawn, retaining walls offer a great mix of function and form.
At South East Formwork, we combine smart engineering with thoughtful design to build retaining walls that are both beautiful and built to last. Whether it’s a small garden wall or a large structural solution, we’ll help you get it right from the ground up.
Get in touch with our team for a quote today.
