Excavation by drill and blast as well as roadheader is getting underway on the Graitery tunnel section of the A16 road in Switzerland, the entirety of which client Astra aims to have completed by 2012.
Contractor Marti Tunnelbau is using an Atlas Copco Rocket Boomer XE3C and an Eickhoff ET 480 roadheader with a telescopic cutting boom to drive the 2462m long two-lane tunnel through geology consisting mainly of the marls and limestone. The consultant on the project is Bienne-based ATB.
The first cut was at the end of May and initial advance rates are 8m per day on the drives. Excavation support is by Swellex SDR steel arches and shotcrete. Excavation is due for completion in 2010, and then the concrete vault lining will take place to create a 10.5m wide tunnel with a ceiling radius of 5.2m.
Work started on site at Graitery last November, and main construction work for the tunnel is programmed to be completed in mid-2011 to be followed by fit-out work for opening to traffic the following year. Realisation of the project comes long after the initial feasibility studies, which took place over 20 years to 1984.
The Graitery section is one of many sections of the A16 that remain to be completed along the route. The most completed sections are closer to the French border while the main tunnelling work remaining to be done is to the south, either side of the main section remain, Griatery – such as at Moutier.
The US$109M contract to build the Graitery section of the route is being funded by the state and the cantons of Berne.
Atlas Copco RB XE 3C starts work at Graitery on the A16, in Switzerland Altas Copco Excavation underway at the neighbouring Moutier section of the A16 Excavation
