Project Description

The 57 km long Gotthard base tunnel in Switzerland is the core piece of the first flat-country railway line crossing the Alps and it is scheduled to open in 2012.

The Consortium IGS under the overall management of Sika Bau AG/ Zürich has taken the order for installation of a drained waterproofing membrane for the TBM-driven sections Bodio (16.5 km) and Faido (15.1 km) including the multifunction area Faido.

Project Requirements and Solutions


The waterproofing system is installed by mechanized operation scaffolding on a shotcrete surface with a surface evenness of 10:1. To support the optimal material characteristics (e.g. biaxial-elongation) to span joints, cracks, fissures and gravel pockets, a loosely laid (spot fixed) plastic sealing membrane is recommended.

Fixing discs (roundels) including a Hook & Loop tape are installed to provide adequate support and a close fit over the entire shotcrete surface. The waterproofing membrane backed with a 200 g/m2 PP geotextile is laid inside the tunnel as a contra part to the Hook & Loop system with sufficient slack to prevent overstressing during concreting.

Sika Products

In addition the following Sika product was used in the project

  • Sikaplan® 14.6 Neat Felt 200

Check out more information about Sika construction products in the Swiss market

Project Participants

Client: AlpTransit Gotthard AG
Project Management: AlpTransit Gotthard AG
Project Design + Site Management: Ingenieurgemeinschaft Gotthard- Basistunnel Süd
Contractor: Consortium TAT
Lead Contractor: Zschokke Locher AG
Membrane Applicator: Consortium IGS
Lead Contractor: Sika Bau AG
Zürich Commercial Management: Tecton AG