Erding near Munich

Erdinger Ringschluss

The new rail link at Munich Airport is being built beneath the runway

New rail link beneath the airport

The Erdinger Ring closure comprises several sections of track designed to expand the rail network in the vicinity of Munich Airport. The extension of the existing tunnel will create the structural conditions necessary for S-Bahn and other trains to pass through the airport in future. The new line connects to the existing railway tunnel to the east and runs beneath parts of the airport site. Even before trains could run on the new link, the tunnel structures for future rail operations were constructed beneath the runway, operational areas and transport routes.

Tunnelling beneath the airport site

The tunnel structure was constructed in sections using both open-cut and cover-and-cut methods. The project also included three emergency exits and nine culvert structures. For the construction pits, around 50,000 m² of diaphragm walls with wall thicknesses of between 80 and 100 cm were constructed. The diaphragm walls extend up to 20 m deep into the subsoil. The tunnel was constructed in 18 construction pits. Underwater concrete bases, each 1.40 m thick, were used for horizontal waterproofing. To secure the construction pit for the approximately 306 m long ramp structure, a further 8,000 m² of sheet pile walls were installed.

Special civil engineering works beneath the apron

Part of the railway tunnel runs beneath the eastern apron area of the satellite terminal. Around 250 m of tunnel structure was constructed in this section. In addition to tunnelling, the works also comprised the dismantling, restoration and technical fit-out of around 10,000 m² of Airfields. Tunnelling, special civil engineering and work on the surface had to be co-ordinated section by section. For the special civil engineering, diaphragm walls, sheet pile walls, underwater concrete bases as well as dewatering measures were used. Together, these formed the excavation enclosure and waterproofing for the underground structures.

Construction between the runway and the railway tunnel

From the start of the runway closure, nine months were available for the construction of the tunnel section and the restoration of the affected airfields. The individual work stages were therefore carried out in coordinated construction phases. In addition to the tunnel and specialised civil engineering works, the technical installations, the airfields and the various trades within the construction site had to be co-ordinated. PORR Special Civil Engineering, pile driving and dewatering were involved in the excavation of the construction pits and the construction of the underground structures.

The basis for the Erdinger Ring closure

The extension of the railway tunnel created a new section of line beneath Munich Airport. The tunnel and ramp structure forms the structural link between the existing tunnel at the satellite terminal and the sections of the Erdinger Ring closure to the east. Where airfields lie on the surface, the foundations for a new rail link were gradually laid beneath them. Diaphragm walls, underwater concrete bases, sheet pile walls and tunnel sections together form the underground structure beneath the airport grounds.