A retaining wall resists the lateral pressure of soil to prevent slope failure. They're essential for landscaping, driveways, foundations, and hillside construction.
Types
- Gravity wall: Uses its own weight to resist soil pressure (stone, concrete)
- Cantilever wall: Reinforced concrete L-shape, most common for 4–25 ft heights
- Sheet pile: Interlocking steel sheets driven into ground
- Anchored wall: Cables or rods anchor wall to rock/soil behind it
Design Rule of Thumb
Base width ≈ 50–70% of wall height. Walls over 4 ft typically need engineering and permits.