Albulatunnel II - New Construction
Company | PORR SUISSE AG in consortium |
Principal | Räthische Bahn AG (RhB) |
Location | Preda-Spinas - Switzerland |
Type | Tunneling |
Runtime | 04.2015 - 12.2022 |
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. During all work on the new, single-track railway tunnel, railway operations could be carried on at the existing Alubla Tunnel I.
The centre distance to the old tunnel is 30m. The two tunnels were 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 were carried out simultaneously from both portals, Preda and Spinas. They were 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 necessitated the highest degree of structural expertise. Materials management and logistics constituted one of the major challenges in the Albula Tunnel II railway construction project.
Under high mountain conditions - the region is one of the coldest in Switzerland - the following achievements were made:
- Excavation of 700,000t of material
- Processing of 400,000t of Albula granite in the gravel plant; of this, 240,000t of aggregates for concrete were produced
- Production and placement of 105,000m³ concrete
- Installation of 94,000m cable protection conduit (DN 132)
- Installation of 15,000m of sewer pipes (DN200/DN315/DN355)
- Up to 130 workers in operation
- Over 1.0 million working hours
To the SRF report “Breakthrough in the Albula massif”
To the PORR project video “Construction works on the Albula tunnel in November 2018”