Albabstieg Tunnel: Karst Probing and Treatment Measures

Quelle/credit: DB Projekt Stuttgart–Ulm GmbH

Overview of the new line from Wendlingen to Ulm

Quelle/credit: DB Projekt Stuttgart–Ulm GmbH

Geological stratigraphy of the new line from Wendlingen to Ulm

Quelle/credit: DB Projekt Stuttgart–Ulm GmbH

Overview of the project section 2.4 “Alb Descent”

Quelle/credit: DB Projekt Stuttgart–Ulm GmbH

Junction structure main bores/intermediate start

Quelle/credit: DB Projekt Stuttgart–Ulm GmbH

Working directions of tunnel drives

Quelle/credit: DB Projekt Stuttgart–Ulm GmbH

Schematic overview of Albabstieg Tunnel: Geological longitudinal section

Quelle/credit: DB Projekt Stuttgart–Ulm GmbH

Geometry of a karst feature as design assumption

Quelle/credit: DB Projekt Stuttgart–Ulm GmbH

1 to 3 m wide karst crevice (blue) and possible location related to the tunnel cross-section as design assumption

Quelle/credit: DB Projekt Stuttgart–Ulm GmbH

Karst crevice parallel, eccentric in the tunnel, as design assumption

Quelle/credit: DB Projekt Stuttgart–Ulm GmbH

Advance karst probing

Quelle/credit: DB Projekt Stuttgart–Ulm GmbH

Karst probing during tunnelling

Quelle/credit: DB Projekt Stuttgart–Ulm GmbH

Karst features in solid limestone (photo documentation and face sketch)

Quelle/credit: DB Projekt Stuttgart–Ulm GmbH

Doline in the freshwater molasse (photo documentation and face sketch)

Quelle/credit: DB Projekt Stuttgart–Ulm GmbH

The new line from Stuttgart to Ulm is part of the new trans-European Main Line from Paris to Budapest. It crosses the Swabian Alb and is divided for planning purposes into the sections Albvorland, Albaufstieg, Albhochfläche, Albabstieg (Alb foreland, ascent, high plain and descent) and the conversion of Ulm railway station. While the high plain of the Alb is predominantly characterised by open-air line, the sloping sections each side are dominated by long tunnels. The areas have similar geology, with karstified white Jurassic limestone being the most frequent formation. For the construction of a structurally stable and serviceable high-speed permanent way, careful handling of the karst is essential. The present article presents the concept for karst investigation and treatment for the Alb descent.

The article includes selected investigation results and the corresponding treatment measures. The decision, whether and what treatment measures are necessary, is made on the basis of general definitions about relevant cavity sizes depending on their spatial location in relation to the tunnel.

This is generally based on the findings of the Karst Working Group, which performed the corresponding fundamental work for the new line from Nuremberg to Ingolstadt on the Franconian Alb. The special situation of karst probing and treatment in mined tunnelling is described through the example of the...