SSAB has developed a totally new type of RD pile wall to replace mainly sheet pile walls in demanding soil conditions. In the new wall the male interlock profile has been formed directly to the pile pipe.

The pile pipe with integrated male interlocks is produced by longitudinally welding at the same line as SSAB’s micropile sizes RD115/8 – RD320/12.5. The main dimensions of the piles and the wall can be seen from Figure below. Female interlock is fastened to pile pipe by intermitted welds. The female interlock is produced at SSAB’s cold forming line at Toijala.

The first pile of the wall has only male interlocks. All other piles have also one female interlock profile. The installation can continue to both directions from the first pile.

Comparison to sheet pile walls

Main purpose of the new wall is to replace sheet piles in demanding soil conditions where contractors are facing often serious problems during installation. There might be some hard soil layers or some other obstacles in the ground, which sheet piles cannot penetrate.
The new RD pile wall is made to replace the sheet piles in such cases. The comparison table below shows the cross sectional properties and bending moment resistances of several common sheet pile wall sizes, traditional RD pile wall sizes and the new wall.

Depending on the situation at the particular project, the comparison can be based on stiffness I, section modulus W or the bending moment resistance Mel of the wall.

Stock product

New wall type will be available as a stock product for fast deliveries. There will be available one pile size, one wall thickness and one steel grade.
Welding of female interlock profile and casing shoe can be done by SSAB or they can be delivered as separate parts and welding can be done at the site.

Special size drill bits

Like all RD pile walls, also the new wall type requires drill bits with unique outside diameter. SSAB has contacted the major drill bit manufacturers. They have shown great interest on the new wall and have already designed new drill bits to fit the requirements of the wall.