It is available in various cross-sections and shapes. They can be hot-rolled sheet piles, cold-rolled, or cold-formed sheet piles. Steel sheet piles durability is enhanced with the aid of corrosion protection measures such as coating and cathodic protection. Steel is the most common form of sheet piles as it has good resistance to high driving stresses,excellent water-tightness, and can be increased in length either by welding or bolting. They are connected by interlocking. There are four basic forms of steel sheet piles, Normal sections, Straight web sections, Box sections and Composite sections.
Sheet piles are commonly used for retaining walls, land reclamation, underground structures such as car parks and basements, in marine locations for riverbank protection, seawalls, cofferdams, and so on. Permanent steel sheet piles are designed to provide a long service life. Vibratory hammers are typically used to install sheet piles. If soils are too hard or dense, an impact hammer can be used to complete the installation. For the development of sheet piles, there are two main techniques: hot-rolled and cold-formed. At high temperatures, hot rolled piles are produced and the interlocks appear to be stronger and more resilient.
Steel sheet piling is manufactured in three basic configurations: “Z”, “U” and “straight” (flat). Historically, such shapes have been hot-rolled products produced at structural mills. Like other shapes such as beams or channels, the steel is heated in a furnace and then passes through a series of rolls to form the final shape and the interlock, which allows the sheet piles to be threaded together. Some use a cold-forming process in which steel coil is rolled at room temperature into the final sheet pile shape. Cold formed sheet piles have hook and grip interlocks.
Z-shaped sheet piles are called Z pile because the single piles are shaped roughly like a horizontally stretched Z. The interlocks are located as far away from the neutral axis as possible to ensure good shear transmission and increase the strength-to-weight ratio.
U type sheet piles are U type profiles with interlock at both sides to form the continuous walls, which has center lines in the midle of the double U section walll. U profile sheet piles can stack more stable than any other shapes, so can be used both in permanent and temporary projects.
Flat sheet piles are used for circular cell applications where the cells form a gravity structure. The sheet piles are interlocked together to form individual cells, or a series of cells, and are then filled with soil. Whereas z-type sheet piles require resistance in bending, the strength of the flat sheets come from their interlocks. Flat sheet interlocks are larger than those on z-type sheet piles and are designed to resist significant tensile forces.Flat sheet piles have limited bending capacity.
