After being contested for months, the tunnel contract for the Erstfeld lot at the Gotthard base tunnel in Switzerland has been finally awarded to the AGN JV and work is scheduled to start in April.
The Lot 151 contract involves just over 7.7km lengths of twin bore tunnel, and is the last of five tunnelling packages on the 57km long project. AGN is a JV of local company Murer–Strabag and Strabag of Austria.
In August 2005, AlpTransit Gotthard had awarded the contract worth US$323M (2005 rates) to AGN. The Marti Consortium objected, resulting in the Federal Appeals Commission for Public Procurement referring the award back to the client. Sensitivity analyses were performed on the competing tenders, external specialists consulted and the award to AGN was re-confirmed last May. Another appeal was upheld.
In the final review, AlpTransit Gotthard had independent company Bachtold establish the assessment criteria for judging the tenders, which was acceptable to both bidders. Bachtold concluded the award procedure put neither bidder at a systematic disadvantage, and Bachtold concluded the AGN bid was economically the best.
By the beginning of March, just over two-thirds of the entire excavation works for the Gotthard base tunnel had been completed by the four other lots – Amsteg, Sedrun, Faido and Bodio. In the neighbouring lot to the south, Amsteg, the twin 11.35km bores have been excavated and the 37 cross passages are being completed. The next lot to the south, Sedrun – which has running tunnels of 7.45km and 7.79km – excavation is well advanced and work is set to continue shortly following extensive grout injection since October to limit water ingress.
Last October also saw the second TBM arrive at the Faido section after driving 13.5km, and excavation stopped for maintenance on both TBMs. The machines are to be transported through Faido station and resume driving shortly towards the Sedrun section. The tunnels in the Faido lot are 14.8km and 14.2km, respectively.
The final section, Bodio, which has running tunnels just under 16km long, is excavated and mostly lined. Reprofiling work is underway in a 300m section to increase the diameter by 500mm. Squeezing rock deformed the profile after the TBMs finally managed to pass the location. The reprofiling work interrupted concrete lining for about five months but is almost finished.
The Gotthard tunnel will be the world’s longest when it opens in late 2016.
