Stuttgart–Ulm Rail Project: The Tunnel below the A8 Motorway on the Swabian Alb

Quelle/credit: Bahnprojekt Stuttgart–Ulm

1 Overview of PFA 2.3 Alb plateau

Quelle/credit: Bahnprojekt Stuttgart–Ulm

2 Layout of the tunnel beneath the A8 federal motorway

Quelle/credit: Bahnprojekt Stuttgart–Ulm

3 Tunnel cross-sections

Quelle/credit: Bahnprojekt Stuttgart–Ulm

4 Geological longitudinal section

Quelle/credit: Bahnprojekt Stuttgart–Ulm

5 Construction phase 0 – starting position (above), 1^st construction section (centre) and 2^nd construction section (below)

Quelle/credit: Bahnprojekt Stuttgart–Ulm

6 Aerial shot of construction status 1 (Oct. 13, 2016)

Quelle/credit: Bahnprojekt Stuttgart–Ulm

7 Concreting operations for the invert, walls and ceiling (Sept. 28, 2016)

Quelle/credit: Bahnprojekt Stuttgart–Ulm

8 Excerpt from the anomaly chart

Quelle/credit: Bahnprojekt Stuttgart–Ulm

9 Karst follow-up investigation in the construction trench (May 7, 2016)

Quelle/credit: Bahnprojekt Stuttgart–Ulm

10 Clearing loam-filled columns and redevelopment by filling them with concrete

Quelle/credit: Bahnprojekt Stuttgart–Ulm

11 Cleared karst column (Aug. 29, 2016)

Quelle/credit: Bahnprojekt Stuttgart–Ulm

The tunnel below the A8 federal motorway is located on the Swabian Alb plateau, which is intersected by the new Wendlingen–Ulm high-speed rail route. Reports on the major project and the plan approval section (PFA) 2.3 Alb plateau have already appeared elsewhere in this journal [2], [3], [4]. The tunnel lies close to the highest point of the route, in the third route section of the roughly 21 km long plan approval section (Fig. 1).

The Tunnel beneath the BAB A8

The 377 m long, twin-track tunnel underpasses the motorway at a glancing intersection at the western end of the PFA 2.3 (Fig. 2). It was built in 10 m long blocks by cut-and-cover as a reinforced concrete rectangular frame. The tunnel invert is up to 1.00 m thick. Drainage of the solid slab track in the tunnel is accomplished by lateral discharge lines located in the tunnel drainage system with a nominal diameter of DN 900 below the structure. The 1.00 m thick and up to 7.55 m high frame walls are haunched at the transitions to the up to 1.30 m thick ceiling. All...