Underneath Dortmund city centre

A new route for an existing urban railway is being constructed, partly underground, in Dortmund, Germany. The line will cross the city centre in an east-west direction. Underground tunnel driving was carried out using the New Austrian Tunnelling Method (NATM). Owing to the congested nature of the city, a service shaft and the main excavation were prepared first. The modular Mammut wall formwork system and support frames STB 450 were used for the construction of the single-side walls for the ramps and Ostentor station. The double-tracked upward and downward ramps for the city railway run along the middle of the street and are an open-cut construction. Part of the ramp was covered at a height of 5.39m. Details are given of the roofing process, using table forms made up of the MEP shoring system. The underground construction of slabs up to 2.5m thikc, the horizontal bracing with the MEP shoring system, and the construction of domed slabs with a thickness of 1.10m are described.