Tunnel liner for water proofing of the Tunnel Leutenbach

The expansion of the federal road B14 required the construction of a tunnel to relieve the city of Leutenbach from excessive traffic. 660m of the two parallel tunnel tubes, with a total length of 1 080 m were made by blast construction. Moreover, three rescue shafts were excavated for security reasons - to provide sufficient escape routes.

The AGRU Easy Fix system, combined with hot air mounting, was used to seal the arch to achieve highest performance. Geotextile-backed VLDPE tunnel liner and a textile that is fixed to the shotcrete were installed.

By means of an automatic process, both textiles were thermally bound by using a hot air bar mounted onto the scaffolding. Furthermore, rollers ensured the pressure necessary for joining.

General benefits

• Automated installation of tunnel liners with high weight
• No additives needed, just hot air
• No thermal stress on the geomembranes
• Increased system reliability due to the reduction of welding seams
• For this Project, geomembranes with 4.0m width were used. Therefore, the number of welds could be reduced by 50%.