Project Description

This new-construction project is located at the upper part of Kleine Scheidegg, over 2’100 m above the sea level. Its usable capacity is more than 72’000 m3.

The construction related figures are listed as follows:
Excavation work: 95’000 m3 (50% was Ripper rock)
Topsoil excavation work: 50’000 m2
Preparation work: 45’000 m3
Artificial lake waterproofing: 14’000 m2
Pipes used onsite: 1’900 m
Concrete structure: 800 m3 (site installation)

Project Requirements

This project has difficult conditions because of its location in a high mountain, because the waterproofing membrane should bear big temperature difference: in the morning below 0 degree, while in the afternoon up to 30 degrees.

Material transport was only possible by railway.

The onsite installation required close cooperation between Sika Sarnafil professionals and the contractor. There were waiting periods and some breaks during the waterproofing installation all through the onsite application process.

Sika Solution

  • Waterproofing buildup:
    Protection and reinforcement protection of the lower part:
    Sika® WT Fleece, synthetic fiber felt 1’000 g/m2, 14’000 m2.
  • Waterproofing:
    Sikaplan® WT 5210-25 CE, Basis TPO, material thickness 2.5 mm, 14’000 m2.
    Upper protection layer in the area of berm (stone rolling):
    Sika® WT Fleece, synthetic fiber felt,1’200 g/m2, 4’500 m2.
    Waterproofing of the construction joints in the concrete structure:
    Sika® Waterbar® AF 310.

Project Participants

Owner: Wengernalpbahnen AG, Hardstrasse 14, 3800 Interlaken
Engineer: Mätzener & Wyss Bauingenieure AG, 3800 Interlaken
Geologist: Geotest AG, 3052 Zollikofen
Contractor: ARGE Ghelma AG, 3860 Meiringen

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