The four tracks of Zurich Airport's underground railway station have been renovated and lowered without interrupting traffic.
Between October 2019 and March 2020, Swiss Federal Railways (SBB) undertook the renovation of all four tracks at Zurich Airport station. One of the main objectives of the project was to lower the tracks to make the trains accessible to wheelchair users without having to modify the tunnel structure. The solution was to replace the concrete sleepers on the tracks, which were showing signs of damages after 40 years of operation.
Description
With its high tensile and compressive strength as well as high durability, Ductal® Overlay enables an economical use of materials. Only small quantities of material are required to produce very robust and durable construction elements. For example, it was possible to reduce the height of the new sleeper blocks by 4 to 5 cm and to achieve support points in these areas of only 10 to 15 cm in height.
Optimization
Operation of the station continued throughout the construction phase. Due to the short period of closure (four weeks per track), the ARGE FF Flughafen consortium (Walo Bertschinger AG, C. Vanoli AG and Carlo Vanoli AG) worked in three shifts under the leadership of Walo Bertschinger AG. Delivery of the materials could only be made by rail during the four hours of nighttime closure. As the construction site was not accessible to lorries, the production of concrete was a real challenge. Walo organized a local production of the UHPC at the end of the track and developed an autonomous wagon to deliver the product direct to every block to be build
Application
Logistics was one of the biggest challenges of this project. All movements of materials had to be planned precisely in advance. Due to the limited space available, it was not possible to store large reserves on the construction site. The cooperation between Walo and Holcim in this phase was very constructive.
