The Chamber of Engineers continues to strive for the demolition of the Libeň Bridge

Prague – Experts in construction associated in the Czech Chamber of Authorized Engineers and Technicians active in construction (ČKAIT) disagree with the approach of Prague's leadership, which canceled the original plan to replace the Libeň Bridge with a new one and decided on its reconstruction. According to representatives of the association, the repair will be expensive, slow, and the resulting parameters of the bridge will be worse than in the case of replacement. They claim that due to the materials, the structure could collapse even during reconstruction, and there is also a risk that the city will lose its building permit and will have to prepare the project again for years. The Deputy Mayor for Transport, Adam Scheinherr (Prague Together), responded by saying that they are not independent experts.

The Libeň Bridge, built in 1928, is in a state of disrepair and has not been completely repaired since it was built. Last year, it had to be temporarily closed to cars and public transport due to its critical condition. The previous leadership of Prague planned to demolish the bridge and replace it with a new structure. This decision was supported by a commission in the council that included members of ČKAIT. However, the current city leadership decided on a repair after the elections.

According to the representatives of the association, the chosen reconstruction plan is problematic for several reasons. They claim it does not meet the conditions of the original building permits, which could mean the need to start from scratch. "You cannot change the basic parameters, if we proceed this way, we will never build anything," said designer and university educator Jan Vítek. He added that the original project for the new bridge began preparation in 1997.

According to Milan Kalný from ČKAIT, the original arches were built from substandard concrete, which has about half the strength of current materials. Furthermore, it contains cavities. "The material is very brittle and prone to sudden failure," he stated. The chosen method, where the city plans to add an additional layer of reinforcing concrete to the existing material, could, according to the builder, cause the bridge's arch to collapse during reconstruction. "It is absolutely unrealistic to combine these two materials," he said. Other problematic issues include, for example, questions about utility networks, water flow under the bridge in case of flooding, or the fact that the plan only addresses the bridge over the Vltava River and not the several other bridges that make up the complex.

According to Lukáš Vráblík from ČKAIT, new bridges are built for a lifespan of 100 years, while a repair guarantees only half that time, and that is provided constant monitoring and diagnostics are maintained. Furthermore, the costs of the reconstruction are similar according to experts from the Klokner Institute for both complete reconstruction and the construction of a new bridge, and they may even increase. "Cost increases in similar reconstructions can sometimes be around 50 percent," Kalný stated.

According to Prague Deputy Mayor Scheinherr, the builders associated in ČKAIT are members of design offices and advocated for the demolition and construction of a new expanded bridge as members of the commission in the previous electoral term. "We are basing ourselves on the independent assessment from the Klokner Institute, which presents only facts; details about the bridge's structure are publicly available on the website of the Technical Road Management. The study was also independently assessed by a professor from the Swiss University of Lausanne and a specialist in bridge reconstruction, Eugen Brühwiler. I fear that the aim is merely to delay the work on the Libeň Bridge just at the moment when it has finally and successfully begun after years," he stated.

The council selected the next steps at the end of this April, based on an expert report from the Klokner Institute, which proposed four possible variants. The council chose the one that plans strengthening rather than replacement of the existing bridge's structure over the Vltava. According to representatives of the capital city, the repair should last 32 months and take place from September 2022 to April 2025. The costs for the reconstruction of the bridge are estimated at about 480 million crowns, with an additional 80 million for the relocation of utility networks.

ČKAIT is a professional organization that brings together more than 30,000 authorized engineers and technicians who have been granted authorization in the field of construction. This allows them to prepare project documentation for construction.