Skip to content

Erdinger Ringschluss suburban rail tunnel, Erding

Facts and Figures
Company PORR Spezialtiefbau GmbH
Principal The S-Bahn Tunnel Erdinger Ringschluss consortium
Location Erding - Germany
Type Construction pits
Runtime 01.2018 - 06.2021

Diaphragm wall and jet grouting works as part of main contracting services.

Munich airport is currently only accessible from the west via two suburban railway lines (S1 and S8). These lines run via Ismaning and Neufahrn and terminate at the rail head under the central section of the airport.

An expanded rail connection to the east will significantly improve access to the airport. As part of the Erdinger Ringschluss circular rail link, the FMG is extending the existing suburban railway tunnel by approx. 1,800m to the east in the area of the existing and planned air traffic areas of the airport. PORR and PORR Spezialtiefbau were contracted to complete these works in consortium.

A permanent diaphragm wall construction

Tunnelling works were completed within a buttressed diaphragm wall construction pit with underwater excavation and an underwater concrete slab. The works were carried out in 18 construction stages (docks) using the cut-and-cover construction method. At the eastern end, the rail line was then laid in a trough construction over several days. A particular feature of this construction method was the execution of a permanent diaphragm wall. Vertical loads will be transferred to the diaphragm wall and then into the subsoil via alcove constructions. The precise connection to the diaphragm wall made it unnecessary to install additional rear anchoring to prevent the underwater floor slab from lifting.

Passing under the apron

The challenging demands of RAMP 3 were able to be successfully overcome. Work began in the apron area (RAMP 3) on 1/1/2019 with a connection to the existing connection. The six-month construction period encompassed almost 10,000m² of diaphragm wall, jet-grouted waterproof columns for the existing connection, 30,000m³ of underwater excavation and almost 200m of tunnelling, after which the first section was handed over to the FMG on 28/6/2019. Works are expected to continue into 2021.

Technical data / quantities

Diaphragm wall


Diaphragm wall dimensions

d = 1,000/800mm
Depths to 24m

Underwater excavation