Flood protection is a crucial requirement for the HafenCity construction. Since the new suburb is located south of the main Hamburg dyke line along the ‘Zollkanal’ canal, a dedicated solution had to be developed to protect it from storm surges.
WK Consult deliverables:
On-site construction management
approx. EUR 3.7 million
The existing road infrastructure was to be adapted to the urban development of the eastern HafenCity and developed into a flood-protected standard. To achieve this, the street ‘Versmannstrasse’ is built east of HafenCity University up to ‘Freihafenelbbrücke’ to the north and elevated to a flood-protected level of approx. 8.30 to 9.10 m above mean sea level.
To improve the compaction behaviour of the planned load-sensitive grounds there, a temporary overfill to 12 m above sea level is envisaged. The screening wall is intended to absorb the height difference between the new road surface and the DB train tracks. In addition, it serves to minimise the effects of horizontal and vertical ground deformations and to prevent clay from the soft layers being pushed onto the DB train tracks to an acceptable degree.
Since the organic ground in the subsoil (soft layers) is extremely powerful and load-sensitive, the screening wall had to be designed as a massive diaphragm wall back-anchored in partial areas that is deeply embedded in the ground.
To reduce the wall load, five approx. 12 m wide rows of concrete columns are arranged in a grid of approx. 2.6 m directly in front of the screening wall to improve the subsoil. An approx. 70 cm thick foundation bed encased in geotextile was installed on the concrete columns.