Sheet Piles are by definition, structural units which when connected one to another, will form a continuous wall, generally for retaining earth or excluding water. Individual pieces or pre-interlocked pairs, are installed by driving them into the earth using impact hammers, vibrators or by water jetting. In functioning as a wall, the sheet piling acts as a beam under load and therefore requires the capability to resist bending. In certain applications, ability to resist bending is not important but strength of interlock is.
Sheet Piling is manufactured in three basic configurations "Z", "U", and "Straight". They can be formed either "Hot Rolled" or "Cold Rolled". A recent development to the industry is the production of some sheet piling shapes by the cold-forming process in which hot rolled sheet sheel is fabricated into traditional sheet piling shapes. These new additions to product availability contain interlocks which are considerably different from the hot-rolled product. Manufactured from a hot-rolled coil of sheet, it is slowly fed through a series of rollers which gradually bends or forms the steel into its designated shape.
The "Z" type configuration for sheet piling is the strongest and most efficient. These shapes resemble wide-flange beams, having a web and two flanges. Since the interlocks are located out on the flanges at maximum distance from the neutal axis, a higher section modulus for resisting bending moments is provided. Z- shapes have traditionally been used for deeper walls and heavier cvonstruction projects. However, they are now supplanting the arch or "U" shape for lighter work as more light-weight Z-shape have been introduced into the marketplace.
U-shapes resemble the hot-rolled channel sections produced on structual mills. The interlocks are formed on the web ends and interlock with their opposing mate along the centerline of the wall.
