Stuttgart

Untertürkheimer Kurve railway tunnel for Stuttgart 21 (Lot 2A)

Tunnel, trough and emergency access structures for Stuttgart 21

Three structures for the Untertürkheim curve

The scope of works comprised: The structures form part of planning approval section 1.6a of the Stuttgart 21 rail project. This section connects the future main station with the lines towards Obertürkheim and Untertürkheim.

• an open-cut tunnel approximately 150 m long
• a trough structure with a total length of 480 m
• an emergency access route beneath the track layout

Tunnel and trough structure for the new route

The open-cut tunnel as well as the trough structure serve to connect the Ober-/Untertürkheim tunnel, which was excavated using mining methods, to the existing line. The structures form part of the future route in the Untertürkheim area and have been integrated into the existing railway infrastructure.

Special civil engineering as well as railway infrastructure

The sheet pile walls and bored piles required for the structures were installed by PORR special civil engineering. In addition, the works included: The services were coordinated with the requirements of railway operations and the infrastructure.

• Water drainage measures
• Temporary bridges
• Drainage systems
• Traffic facilities in the track area
• Track construction
• Overhead line construction
• Railway technical installations

Concrete works under special requirements

Specially formulated concrete mixes were used for the construction of the tunnel and trough structures. On warm days, the fresh concrete was cooled to ensure compliance with the specified placing conditions. Concrete delivery and placement were coordinated with the on-site construction schedule. The concretes used were developed specifically for this project and tailored to the requirements of the structure.

Emergency access road and shell

The shell on the emergency access road was completed in 2016. The shell on the tunnel and trough structures followed in October 2020. Once the shell was complete, the structures were handed over to the subsequent finishing trades.

Part of Stuttgart 21

The Untertürkheim Curve forms part of the infrastructure measures for the Stuttgart 21 rail project. The construction of the tunnel, the trough and the emergency access road laid the foundations for their subsequent integration into the new rail infrastructure.