Steel Sheet Piling: Uses and Characteristics

Sheet piles are structural components that, fixed into the ground to a suitable depth, form a true vertical wall called a sheet pile wall.
Made from various materials, in different thicknesses and types, these components are primarily used to protect the excavation area or the general work area. In this article, we will outline the characteristics, uses, and reference standards of sheet piles.

What Is a Sheet Pile?

The term sheet piles refers to construction elements, mainly used in steel, that through a vertical interlock create a protective wall. This protection serves two main purposes:

To contain the pressure of the soil;
To contain the pressure of water.

Steel sheet piles, therefore, are used for hydraulic functions and/or soil support and can be permanent or temporary. In the next paragraph, we will better understand this important distinction.

Use of Steel Sheet Piles

Depending on the required uses, sheet piles can be employed temporarily or permanently.

A sheet pile anchored to the ground temporarily and movably is generally used in internal excavation areas of a construction site. In this case, their use serves to protect the excavation, especially in particular soil conditions, and the sheet pile wall will be removed at the end of the work.

A permanent or fixed sheet pile, on the other hand, is used in works such as the construction of quays and ports, protection of riverbanks and channels, retaining walls, underground car parks, underpasses, etc. Also, in this case, the goal is to protect the work area but, above all, to contain the soil and water.

These are structural components employed in heavy carpentry works and, given their exposure to corrosion phenomena, can be subjected to hot-dip galvanizing to increase their durability.

Types and Thicknesses of Steel Sheet Piles

The two main types of steel sheet piles are those with a U-section and those with a Z-section.

U-section: with thicknesses ranging from about 8 mm to just over 20 mm, these are construction components with excellent stability and resistance to corrosion. The latter characteristic is specifically related to the increase in thickness at critical points;
Z-section: with thicknesses that can reach 17 mm, these components make the driving (anchoring) phase simpler thanks to their wide width.

Generally, sheet piles are anchored to each other through a vertical Larsen-type joint that also allows slight rotations of the sheet pile wall (max 5°) to adapt it to slight curves.

Regulations Related to Sheet Piles

The regulations related to sheet piles are of two kinds, concerning the product and design.

Product regulations concern the marketing of components that respect the reference dictates:

UNI EN 10248-1:1997 – Hot rolled sheet piling of non-alloy steels – Technical delivery conditions;
UNI EN 10248-2:1997 – Hot rolled sheet piling of non-alloy steels – Dimensional and shape tolerances;
UNI EN 10249-1:1997 – Cold formed sheet piling of non-alloy steels. Technical delivery conditions;
UNI EN 10249-2:1997 – Cold formed sheet piling of non-alloy steels. Dimensional and shape tolerances.

Design-related regulations concern the methods of ideation and elaboration of components in line with what is reported in the norms:

UNI EN 1993-5:2007 – Eurocode 3 – Design of steel structures – Part 5: Piles and sheet piles
D.M. 17/01/2018: Technical standards for constructions. For further information about sheet piles, subscribe to our newsletter.