Slab Track Austria for the upgrade of the Maribor-Šentilj railway line

Background and summary.

The project is a part of the modernisation and upgrade of the single-track railway section between the Slovenian city of Maribor and Šentilj near the Austrian border. The objective is to close the existing gap on the Core Trans-European Transport Network (TEN-T) Baltic-Adriatic Corridor, a line which is one of several important international freight connections. It links Slovenia, including the main port of Koper, to the direct connection of Austria and the Mediterranean corridor.

One part of the project was the construction of the new 1,528m Pekel tunnel near Šentilj. Alongside a new rail track between Počehova and Pesnica was built, including a 897m viaduct over the Pesnica river valley. The route is designed for a double-track railway line and will increase both the carrying capacity and speed. Furthermore, the line will increase safety and efficiency according to the latest European railway standards. In the first phase the left track was built, while the right track is planned for the future. The STA, short for Slab Track Austria, system was installed in the tunnel, in the viaduct and in short sections at grade that provides access to the tunnel portal areas as well as transition to the ballast areas. In total, this makes a length of 2,924m of slab track.

System innovations to meet today’s railway requirements.

Various slab lengths from 2.58m to 5.16m have been designed to suit discontinuities such as construction joints in the track supporting structure.

According to the best practices from Austria and Germany and the EU rail safety requirements, the entire tunnel section with slab track will be utilised in conjunction with tyre-accessible precast panels to serve the response vehicles if needed. On the viaduct, slab track was fitted with precast derailment protection panels. This innovative precast panel solution by PORR was chosen over traditional fastened steel guard rail devices based on cost savings, the ease of installation and the possibility of dismantling for maintenance or repair.

In collaboration with FCP, deck-end rotation and displacements on the viaduct were analysed to determine potential conveyed rail stresses. To mitigate this condition, specially designed slabs with reduced creep resistant rail fastenings are implemented at the deck-ends.

Project deliverables.

PORR as the system provider delivered the system design, supplied precast slab components and provided technical supervision and assistance during construction. Part of the production was carried out in cooperation with a Slovenian precast producer under PORR’s guidance. This local partnership is considered as a strong foundation for future slab track projects in Slovenia and could further develop business in the adjoining regions.