TOP OF EUROPE WITH NEW UNDERGROUND VISITOR ATTRACTION

Sika products have been specified for a new underground attraction at the Jungfraujoch, the "Top of Europe", at an altitude of nearly 3,500 meters.

The Jungfraubahn rack railroad takes visitors from the Kleine Scheidegg pass to the Jungfraujoch, at an elevation of 3,454 meters. This groundbreaking feat of engineering was opened on Swiss National Day (August 1) in 1912 after a 15-year construction period (1896-1912), having cost a full CHF 16 million. Open 365 days a year, the Jungfraubahn railroad covers a distance of 9.34 kilometers and overcomes a height difference of 1,393 meters. As early as 1913, the Jungfraujoch attracted some 42,880 visitors.

NEW ADVENTURE TUNNEL: BEST ALL-WEATHER ATTRACTION

100 years on, the annual tally has risen to 700,000. To guarantee an exciting visit even in poor weather, the Jungfraubahn AG will mark its 100-year anniversary with the opening of a new 255 meter long adventure tunnel. This direct underground link between Sphinx Hall and Ice Palace is certain to become the best all-weather attraction anywhere in the Alps.

CIRCULAR TRAIL WITH SHOWCASE NICHES

The adventure tunnel will take the form of a circular trail featuring various attractions in a sequence of caverns (showcase niches). It is designed for wheelchair and fork-lift access. Two travelators, 43 and 70 meters long, will be provided along the inclined sections. Part of the installation caverns and muck tunnel will be used for storage purposes.

The new route leads visitors from the Sphinx Hall to the existing Anchorage Tunnel, overcoming a height difference of eight meters. A newly built passageway branches off the Anchorage Tunnel to join up with the access tunnel to the Ice Palace.

An approximately 60 meter muck tunnel was built to remove spoil from the excavation face. This runs south-east from the Aletsch Glacier exit to the glacier, where the uncontaminated material is tipped into a crevasse.

The tunnels and caverns were mainly excavated by blasting, with tunneling machines reserved for the sensitive sections. The tunnels and caverns were stabilized with shotcrete, mesh and rock bolts. All works except the muck tunnel were waterproofed by an umbrella membrane covered over by a minimum of twelve centimeters thick, reinforced shotcrete lining. A conventional drainage solution with perforated pipes and French drains was adopted. The tunnels and caverns incorporate a reinforced-concrete base slab, placed over a cable conduit run.

LOGISCTICS AND GOODS SHIPMENTS

All shipments are made by road as far as Grindelwald-Grund station, from where they are taken by the Wengeneralpbahn rack railroad to the Kleine Scheidegg pass. Here, the materials are reloaded onto the Jungfraubahn railroad and transported to Platform three of the Jungfraujoch station.

HIGH-GRADE CONCRETE ON 3,460 METERS ABOVE SEA

The project called for a concreting concept capable of accommodating low temperatures, averaging out at -8.2°C across the year, and ground temperatures potentially as low as ‑15°C.

The adopted solution involves the use of dry-mix materials, delivered to the site in big bags. Here, the dry mix is poured into a wheeled mixer and mixed with water. The 255 meters addition to the complex tunnel system at the Jungfraujoch, Europe's highest-altitude railroad station at 3,454 meters above sea level, looks certain to boost its pulling power.

USED SIKA PRODUCTS

Quantity                  Sika Products
2,500 t 
0-8 mm shotcrete
40 t
Sika® Sigunit® L53 AF
4 t Sika® ViscoCrete® 3082
1,000 t 0-16 mm in-situ concrete
3,000 m2 Sikaplan® WT
12 t Sika® Rock-Gunit
8 t Sika® Shot-3
Additional products
SikaFuko® Swell 1, Sika®-4A, Sika® Separol®-5 S and SikaPump®-Start 1