Land reclamation for production of the new Airbus

Project description

The main problem faced was construction in very soft soil (cu between 0.4 and 10 kN/m2) with thicknesses between 8 and 14 m. The area concerned is also located in a tidal zone, with soil movement into the Elbe river not being permitted. The original design solution for solving the stability problem asked for a 2.5 km long sheet wall to a depth of 40 m. The GEC, alternative solution, saved 35,000 tonnes of sheet piling, 15 ha of reclamation area, 1.1 million m3 of sand filling, 8 million litres of fuel consumption and more than one year of construction time.

Solution

Approximately 60.000 pieces Geotextile Encase Sand Columns (GEC) with lengths varying between 4 and 14 m were installed at Mühlenberger Loch in Hamburg as a foundation system for a 2.4 km long dike. The new dike encloses a polder creating 140 ha of new land for the extension of the existing DASA Airbus plant (EADS) in Hamburg-Finkenwerder required for the production of the new Airbus A380. This enclosed area required to be raised up to 3 m above sea level. The geotextile casing with a diameter of 800 mm provides radial support to the sand column in the soft layers. The distance between the columns centres is generally between 1.7 and 2.4 m. Over the GEC a horizontal bearing and equalising reinforcement is installed before construction of the dike is undertaken.

Benefits

• Major savings in steel, sand transport, reclamation area
• Shorter construction times
• Extensive reduction in settlements
• Substantial cost savings
• Can be used in soils with cu < 15 kN/m²