We provide services in foundation works including:

1. Retained earth

Retained earth is soil constructed with artificial reinforcing. It can be used for retaining walls, bridge abutments, seawalls, and dikes.

Retained earth walls stabilize unstable slopes and retain the soil on steep slopes and under crest loads. The wall face is often of precast, segmental blocks, panels or geocells that can tolerate some differential movement. The walls are infilled with granular soil, with or without reinforcement, while retaining the backfill soil. Reinforced walls utilize horizontal layers typically of geogrids. The reinforced soil mass, along with the facing, forms the wall. In many types of retained earth walls, each vertical fascia row is inset, thereby providing individual cells that can be infilled with topsoil and planted with vegetation to create a green wall.

Retained earth wall

The main advantages of retained earth walls compared to conventional reinforced concrete walls are their ease of installation and quick construction. They do not require formwork or curing and each layer is structurally sound as it is laid, reducing the need for support, scaffolding or cranes. They also do not require additional work on the facing.

2. Tie-back – ground anchor

A tieback is a structural element installed in soil or rock to transfer applied tensile load into the ground. Typically in the form of a horizontal wire or rod, or a helical anchor, a tieback is commonly used along with other retaining systems (e.g. soldier piles, sheet piles, secant and tangent walls) to provide additional stability to cantilevered retaining walls. With one end of the tieback secured to the wall, the other end is anchored into earth with sufficient resistance.

Tiebacks for slope stabilization

Tiebacks are drilled into soil using a small diameter shaft, and usually installed at an angle of 15 to 45 degrees. It can be either drilled directly into a soldier pile, or through a wale installed between consecutive piles. Grouted tiebacks can be constructed as steel rods drilled through a concrete wall out into the soil or bedrock on the other side. Grout is then pumped under pressure into the tieback anchor holes to increase soil resistance and thereby prevent tiebacks from pulling out, reducing the risk for wall destabilization.