Larssen Interlocking Sheet Pile Sections

Sheet piles are interlocking, shaped sections of steel that are used to create structures like retaining walls and cofferdams. Retaining walls, by definition, are walls that hold back water or earth. These walls are designed to resist lateral pressures and prevent seepage.

Some of the most widely-used sheet pile is the Z-shape, hot-rolled sheet pile. Z sheet piles are known by the continuous forms of the web, and the specific location of the interlocks. Z-pile’s specific shape help improve the accuracy of alignment during placement.

We previously discussed some common steel sheet pile options, with ball-and-socket or thumb-and-finger interlocks. A third, very popular type of interlocking system is the Larssen interlock. Although the original Larssen sheet pile was a U-shaped section, all Z-shape sheet piles today are based on the original patent, which introduced the concept of the ‘wave shape’ to sheet pile.

The Larrsen Interlocking System

Tryggve Larssen, State Chief Engineer at the City of Bremen in Germany, obtained a patent for the world’s first deep, hot-rolled section. Prior to this, sheet piles had been largely made from wood, and any steel sheet piles were flat sections. Larssen’s patent created a wave shape when assembled, with alternating indents and outdents.

The original Larssen sheet piles had the interlocks manufactured separately from the pile itself. The first rivet-less Larssen interlock was produced in 1914, a practice that continues today, with all Larssen interlocks fabricated upon the neutral axis.

The Larrsen interlocking system is highly resistant to seepage because of its shape and tight connection. The interlocking system assists teams with pitching and driving by controlling the swing radius tightly. The AZ, NZ, ZZ, Hoesch, and ESZ variations of sheet pile discussed below all utilize the Larssen interlocking system, with the interlocks located on the neutral axis of the sheet.

AZ

AZ pile have wider profiles than PZ and PZC sheet pile, and thicker steel at critical corrosion points which helps improve its performance against corrosion. They have a consistent thickness throughout the flange and web.

NZ

NZ sheet pile are more light-weight and wider than traditional PZ and PZC sheet pile. Like the AZ sheet pile, NZ sections’ web and flange thicknesses are constant. Also similar to the AZ sheet pile: NZ sheet piles’ sections are named using its section modulus. NZ sheet pile is manufactured in the United States – as of the writing of this article this is the only Larssen interlock sheet pile that is U.S. domestic.

ZZ

Unlike AZ- and NZ-style sheet pile, ZZ sheet pile have an inconsistent flange and web thickness, though the differences are small: a ZZ19-700 has a web thickness of 9.5mm (0.375 inches), and a flange thickness of 9.6mm (0.378 inches). They are slightly lighter than same-width AZ and NZ sections.

Hoesch

Similar to ZZ sheet pile, Hoesch sheet pile’s web and flange thicknesses are inconsistent, though the differences are not always as small as above. The larger (and heavier) a section of Hoesch pile, the greater the difference: an H1707 has a web thickness of 8.7mm (0.343 inches) and a flange thickness of 8.5mm (0.335 inches), but an H3607 has 16.8mm (0.661 inches) web and 10.8mm (0.425 inches) flange thickness.

ESZ

ESZ sheet pile are deep-profiled sections that have a continuous web, which works to optimize shear load transfer. This type of sheet pile sports a deep profile. Because of this, the inertia is increased and deflection is reduced. Like the AZ and NZ sheet pile, ESZ sheet pile have a consistent web and flange thickness throughout.

Buy and Sell Used Sheet Pile with Eiffel Trading

Eiffel Trading currently has many types of used sheet pile for sale (including PZ/PZC sheet pile, PS sheet pile, AZ/NZ/ZZ/Hoesch sheet pile, and cold-rolled sheet pile) as well as used combined wall systems.

All of our listings are constantly being updated, but if you don’t see what you’re looking for, create a wanted listing for free.

Ready to sell your used heavy equipment or construction material? List your products today for free on Eiffel Trading’s online marketplace.

If you have any questions or would like additional information, please call us at 1-800-541-7998 or email sales@eiffeltrading.com.