During the renovation of the Libeň Bridge, a replica of the bridge will be created on the original pillars

photo: IPR Prague

Prague - Prague road workers will have to demolish a larger part of the Libeň Bridge over the Vltava River during its reconstruction than originally anticipated. The pillars will remain, on which a replica of the original bridge will be created according to the design of architect Pavel Janák. The reason for this is the results of static tests. Some of the originally planned methods are now prohibited by new European legislation. This was stated today by Deputy Mayor Zdeněk Hřib (Pirates) and Director of the Technical Administration of Communications (TSK) Jozef Sinčák. According to Sinčák, the cost of repairs, which is 2.1 billion crowns, should not change because of this.

The Libeň Bridge is a complex made up of six bridges and was built according to the design of architect Pavel Janák in 1928. The bridge has never been repaired and is in very bad condition. The consortium of companies that will repair the bridge is led by Metrostav TBR, which also includes the parent company Metrostav and design firms SATRA and SHP.

"We wanted to have certainty, which is why work was done on a detailed static model. The results showed that it is not possible to maintain the extent of the original construction in the volume we originally anticipated. By wanting to build a bridge that meets modern requirements for traffic load from the outset, we decided on a version that will mean replacing a significant part of the structure with a new one," Sinčák stated. "The solution from the original structure will include the pillars, which will be rehabilitated, and a replica will be built on that," he added.

In addition to the results of the static model, TSK also had to take into account the new European legislation, which has been tightened in connection with the collapse of a bridge in Genoa, Italy. As a result, there is a ban on newly repairing structures that are made of plain concrete and are not exposed, making it impossible to see whether they are damaged. "Here, the structure, as it is buried and not visible, the original method proved to be unusable," Sinčák said. The original structure would also not support the so-called tram body, which carries the tracks and other accessories.

TSK has submitted documentation for the building permit for the repair of the first part of the bridge, that is, the section from Palmovka towards the Vltava. Documents for the remaining parts will be ready next year. "The year 2024 will thus be characterized by the completion of design work and the fact that the building permit process will be underway, by the end of the year we could have results, approved projects so that we can start the physical reconstruction of the first phase in spring 2025," Sinčák said.

A completely new structure will be built for the so-called flood bridge on the right bank of the river. The flood bridge serves as protection for the road against flooding. For the original one, it has been evident from the outset, according to Sinčák, that it would not meet the new demands for full load-bearing capacity and lifespan.

The cost of repairs, which is 2.1 billion crowns, should not be affected by the newly chosen reconstruction approach for the Libeň Bridge. According to Sinčák, in some parts the repair will be somewhat more expensive, while in others it will be cheaper. "We still maintain the amount as relevant. I firmly believe that we will remain within this limit," he said.

The bridge is in a state of emergency. In 2018, it was temporarily closed to vehicles and public transport due to this. Last year, diagnostics showed that all arches exhibit the same load-bearing capacity as at the time of construction. The previous leadership of Prague planned to demolish the bridge and replace it with a new structure, but the current city leadership has decided on repairs.