Interlocking Pipe Piles

Interlocking (steel) pipe piles are pile foundation support structural components consisting of SSAW (or LSAW) steel pipes and C-shaped or T-shaped interlocking connectors. Through the interlocking of these connectors, adjacent piles are mechanically interlocked to form an integrated support structure. Their core features include rigid connections, anti-displacement, and leak-proofing, making them suitable for complex pile foundation engineering scenarios such as cofferdam support, deep-water foundation construction, and excavation shoring.

There are three main types of interlocking pipe piles: the C9 interlock, the CT interlock and the socket-and-ball interlock. The method of connecting steel pipe piles varies significantly depending on the type of interlock used. Please see the sample images of the various interlocks below.

There are two main connection methods for C9 lock-type steel pipe piles: the U-shaped sheet pile connection method and the Z-shaped sheet pile connection method. As shown in the figure:

CT-type interlocking joints typically consist of C-shaped small steel tubes and T-shaped steel plates. The C-shaped small steel tubes are welded to the outer surface of the steel pipe piles, while the T-shaped steel plates are cut from I-beams and form a male-female interlocking structure with the C-shaped small steel tubes . The C-shaped component serves as the male joint, while the T-shaped component serves as the female joint; the two connect by interlocking during driving. Compared to traditional locking joints, the CT-type locking joint offers lower driving resistance, and the length of the T-shaped flange is adjustable, facilitating subsequent realignment.