Rail link of European significance

The Wunderline is a cross-border rail link between northern Germany and the northern Netherlands. It forms part of an infrastructure project in north-western Europe. The modernisation and expansion of the existing line are intended to improve connections between the north-western and Groningen-Assen metropolitan regions, increase capacity and reduce journey times. Furthermore, the link is intended to support international rail transport between the Netherlands, northern Germany and Scandinavia. As part of construction phase 1, the track, subgrade and ballast are being renewed and stabilised, amongst other works. In future, passenger trains will be able to travel at speeds of up to 120 km/h on this section of the line.

Special civil engineering as the technical foundation

In the Bunde, Charlottenpolder section, PORR Spezialtiefbau GmbH’s Hanover branch was responsible for constructing sealing slabs in three sheet-pile construction pits for railway underpasses. Each construction pit covers an area of around 50 to 80 square metres. The Silitight 69 soft gel was used to seal the construction pits against infiltrating groundwater.

Silicate gels are frequently used in special civil engineering to create horizontal waterproof bases for construction pits. They are particularly useful where structures need to be protected against rising or infiltrating groundwater. Environmental considerations were also taken into account during the project preparation phase.

Construction in high groundwater conditions

In infrastructure projects, local conditions often place special construction requirements on the construction process. One challenge in the project area was the high groundwater level in East Frisia. Added to this were the constraints of a linear construction site, with, in some cases, long conveyance distances for the pumping equipment. Coordinated execution and close cooperation between all project stakeholders enabled the work to be carried out under the given conditions.

Planning and execution from a single source

A key aspect of the project was its integrated implementation by PORR. Planning and execution were coordinated within a group of companies. This enabled technical requirements to be agreed at an early stage and the work to be prepared. Drawing on its experience in special civil engineering, PORR supported the construction of the excavation base linings and thus the implementation of this infrastructure project between Germany and the Netherlands.