Albulatunnel II - New Construction
|Company||PORR SUISSE AG in consortium|
|Principal||Räthische Bahn AG (RhB)|
|Location||Preda-Spinas - Switzerland|
|Runtime||03.2015 - 05.2020|
A new tunnel to the Engadine.
The Albula tunnel runs through the heart of the Swiss mountains, connecting the municipality of Preda in the Albula Valley to Spinas in the Engadine. The decision was made to build a new tunnel more than 100 years after the existing tunnel was opened. Once Albula Tunnel II has been completed, the existing tunnel will be repaired and converted into a safety tunnel. All work on the new, single-track railway tunnel will be carried out while maintaining railway operations.
The centre distance to the old tunnel is 30m. The two tunnels will be connected via twelve cross passages. The total length of the new Albula Tunnel II is around 5,860m and the excavated cross-sections measure 35 to 46m2 – up to 60m2 in the rauwacke (gypsum-bearing dolomite) regions. The main tunnelling operations are carried out simultaneously from both the Preda and Spinas portals, and will be undertaken for the most part using full-face excavation and blasting methods.
A 110m long section (approximately 1,000m behind the Preda portal) runs through the rauwacke, where complex geological and hydro-geological conditions necessitate the highest degree of structural expertise. Materials management and logistics constitute one of the major challenges in the Albula Tunnel II railway construction project.
The Albula Tunnel II construction site was set up at the Preda portal. It includes a water protection facility, conveyor and transfer belts, and a material and concrete processing plant.© PORR
The tunnelling works for Albula Tunnel II begin with a 230m long section covered by a pipe arch from the stop wall at the Spinas portal.© PORR
The boreholes for blasting the Albula Tunnel II are made with the utmost precision with the aid of coloured markings.© PORR