The Filder Tunnel, which is part of the major Stuttgart 21 project, connects the southern end of Stuttgart’s new subterranean main station with the Filder Plain close to Stuttgart Airport. With a length of 9,468 m it will be the longest tunnel of the Stuttgart–Ulm railway project. The tender envisaged the conventional construction of the two tunnel tubes. In addition to this however, the client authorised the presentation of a range of TBM tunnelling variants using alternative driving and logistics concepts. The contract was awarded to the alternative proposal by the bidder consortium ATCOST21, which envisaged the use of just one tunnelling machine. This solution required the turning of the multimodal machine in a specially excavated cavern.
iC advised the bidder consortium ATCOST21 from the offer phase and has been responsible for the entire execution design of the Filder Tunnel (conventional driving and internal cladding work, tunnelling machines, connecting structures, escape tunnels, …) on behalf of ATCOST21 since 2011. The main design work is virtually complete. One of the final tasks was the design of the turning cavern. The challenges for the designers included the dimension of the cross-section, the transition of the cross-section between the tunnel tubes and the turning cavern with its very flat cut surfaces and large horizontal spans and the requirement to minimise any loosening of the rock and subsidence in order to protect the Wagenburg road tunnel, which is located immediately above the turning cavern. The design and tunnelling work has been successfully concluded and the tunnelling shield was successfully turned around on 30 August 2018.

Glück Auf – and happy tunnelling!