Atypical applications
Steel sheet piles have been used for over a century to build cofferdams in rivers and canals. The interlocks of hot rolled sheet piles are quite watertight, sufficiently to limit the amount of water seeping through them into the cofferdam. However, for high water pressure, interlock sealants or additional measures may be taken to reduce the amount of water ingress.
Deep cofferdams, for instance to build locks and dams in rivers, require multiple strutting levels, of for even deeper cofferdams, such as in the Mississippi river in the USA, large cellular structures using AS 500 sections were used several times. The advantage of steel sheet piles is that they can be recovered and even re-used in the same project a few times.
Small cofferdams are usually built with standard corrugated sections, preferably Z-piles.