AU 20 sheet pile retaining wall (cofferdam) | Munich Airport | DE

The construction of an office building near Munich Airport called for a watertight cofferdam to be built. The groundwater level at the building site was 0.5 to 1.0 m below the surface. To avert technical or economic problems, the top soil was stripped to a depth of about 0.5 m, and sheet piles were installed. To ensure compliance with the fast-track construction schedule, the contractor opted for the most efficient solution: a steel sheet pile structure using the economical AU 20 sections.

The AU 20 was the first section in the hot-rolled AU series. With a width of 750 mm, it is 25% wider than conventional sheet piles, it made for faster driving and superior watertightness due to the lower number of interlocks per meter of wall. No further sealing of the Larssen interlocks was needed. Additional savings of up to 10% on the quantity of steel (relative to a comparable PU 20 section) made the sheet pile wall very economical indeed.

The 11.0 m long sheet piles were driven into the Tertiary soil layers without any problems; in fact, driving performance was outstanding.