How do interlocking steel sheet piles form a quay wall?

Interlocking steel sheet piles form a quay wall by creating a continuous, impervious membrane driven into the ground. The process involves several key engineering steps:1

• Interlocking Mechanism: The piles consist of rolled trough sections featuring interlocking grooves or guides known as clutches along each edge. Each new pile is engaged clutch-to-clutch with a previously driven pile and then driven to the required depth.1
• Structural Configuration: To build lateral stiffness, the convexity of the trough sections is typically arranged to face alternately in opposite directions. This configuration allows for some angular deviation in the clutches, enabling the construction of curved quay layouts.1
• Anchoring: Because the upper portion of the wall is laterally unsupported on the sea side, it is anchored back to resist the thrust of the retained soil. This is commonly achieved using tie rods secured to buried anchors, which are often composed of additional lengths of sheet piling.1
• Completion: The structure is finished by casting a reinforced-concrete cope beam over the exposed heads of the piling to contain and protect them.1