How do tie rods and buried anchors support a sheet-piled quay wall?

In the design of a sheet-piled quay wall, the upper portion of the steel sheetpiling lacks lateral support on the sea side and must be anchored to resist the horizontal thrust exerted by the retained soil.1

To provide this stability, engineers use tie rods that connect the quay wall to anchors buried within the retained soil. These anchors are positioned at a depth beyond the natural slope line of the soil to ensure overall structural stability. Frequently, these buried anchors are constructed from additional lengths of sheetpiling driven into the strata beneath the retained soil.1

The tie rods, typically made of mild or alloy steel and protected against corrosion, are secured to the quay wall either by passing through the piling with large retaining nuts on the exterior or by being attached to welded fixtures on the back of the piling. The latter method is often preferred for its cleaner, more finished appearance. This system allows the space behind the wall to be filled with material that can be treated as natural ground, providing a practical area for installing service ducts and infrastructure.1