Construction of a two-track railway tunnel with a TBM.
Section 3 of the cross-city link is the Weinberg Tunnel, which is 4,537 metres long and runs from the south-western section to the portal in Oerlikon. Lots 3.1 and 3.2 involve the Weinberg Tunnel. Lot 3.1 includes the shaft for the southern section, and the extension of the structure to the new train station. Lot 3.2 involves the 40-metre-deep Brunnenhof shaft, the Weinberg Tunnel, and the rocky section between Brunnenhof and the Oerlikon portal. It also includes the escape and rescue tunnels and their cross-passages to the main tunnel.
Services in detail
Tunnelling techniques for hard rock were used in the first 4,134 metres, with hydroshield technology being used for the remaining 246 metres. Two shells were used to secure the extension work – an outer shell with 30-centimetre-thick reinforced concrete segments, and an inner shell with non-reinforced in-situ concrete, also 30 centimetres thick. In some parts of the tunnel, the thickness of the concrete segments was increased to 60 cm at the base. Reinforcement was added to the inner shell in the regions surrounding the cross-passages.
Conversion from TBM in hard rock to hydroshield technology; traversing the Limmat River with pipe umbrellas, operating the dedicated concrete station at the Brunnenhof installation site; total concrete production: 55,000 m3. Management of the excavated material, up to and including disposal. Use of freezing techniques (icing the ground with liquid nitrogen) between the old and new diaphragm wall for sealing off the shaft in the southern section.