Pilings for Retaining Walls

Sheet Piling

• Sheet piling is a method of reinforcement used in retaining wall construction. Ridged beams, or piles, are vertically driven underground and placed edge to edge to create a seamless sheet of beams. They provide anchorage and support below the actual wall. The retaining wall is built against the reinforcing beams. This type of piling is used for building foundations and basements. Benefits of this type of piling are its ability to withstand vibration and to act as a sound screen.

Concrete Piling

• Concrete piling is resistant to corrosion, provides bulk and weight and has a long lifespan. Concrete's ability to withstand wet conditions is a major reason why this material is often used for piers and seawalls. Concrete pilings are long concrete beams that can be either drilled into the site or poured and set. The pilings are often themselves reinforced with steel bars. These bars are located within the center of the concrete pilings. These pilings provide anchorage and increase the strength and durability of the above-ground retaining wall. The pilings are vulnerable, however, to erosion. When surrounding soil gives way, the pilings can be left behind. Exposed and without soil surrounding it for additional support, the pilings can become unstable.

Landscape Terracing

• Wood planks are also used as pilings but they are less durable and work well for small walls, those 4 feet tall or less. Wood planks or posts are driven vertically into the ground and act as a framework for the rest of the wooden wall. These types of retaining walls, as well as those made of stacked pavers and stone, are often found in terraced landscapes. Small walls do not always require piling but they will benefit structurally from footers and tie-backs.

Considerations

• Retaining walls are also located underground where they serve to protect underground tunnels such as those found in subway systems and mines. In these situations, struts are often strategically placed between the walls to provide greater reinforcement against the weight of soil and rock.