Renovating bridge piers
What started seven years ago as a survey supported by Prangl will now also be completed by Prangl: the bridge piers on the Jauntal bridge are being renovated. The position of the bridge piers in the Drava required an extraordinary concept even back then in order to be able to perform the work.
Expansion of the Jauntal bridge
The 130 kilometre long Koralm railway has been under construction since 1999 and will provide the first direct rail connection between Styria and Carinthia. Thanks to a speed of up to 250 km/h, the train journey between Graz and Klagenfurt should take just 45 minutes. The 430 metre long Jauntal bridge is a vital section. At a height of 96 metres above the water level of the Drava, it is the highest railway bridge in Austria. In order to meet the requirements of the high speed railways, the single-track supporting structure is being replaced with a double track.
Special concept required
As part of the modification works, the four bridge piers with heights of between 60.5 and 76.9 metres are the only elements that will remain. They were already subjected to a meticulous survey in 2015 with Prangl's help. This was followed by the release of the structural analysis and finally the start of the general renovation to the piers. The Prangl experts were again called on to provide assistance. Due to the height of the piers, the exposed position in the middle of the Drava, the extreme drop and the rough terrain on the river banks, the same as the first time, neither mobile cranes nor aerial work platforms were able to be used.
The solution: Suspended access platforms
Eight suspended access platforms with a basket length of 8 or 12 metres and a payload of up to 760 kilograms were brought on-site, i.e. to the banks of the Drava. There, they were loaded onto floating platforms for each of which a landing stage was erected in the vicinity of the piers. The suspended access platforms then made their way to the relevant pier by pontoon. A special structure was used to fasten the suspended access platforms to the bridge piers. In this way, the required renovation work was able to be performed even in less accessible places on the pier.
Equipped for the Koralm railway
The bridge piers were cleaned with high pressure, all cracks and holes were filled and then coated again. They are therefore well equipped for the new era of the old railway line. The planned official opening date for the new bridge is the timetable change in December 2023, as that is when the Koralm railway will start running, at least on the Carinthian side. The high speed line is planned to be fully operational as of 2025. We at Prangl are proud to have been involved in such an important construction project and to have made such an important contribution.