From the beginning, the whole situation was complicated by the fact that Hlávka Bridge is a protected monument. Therefore, all intended interventions had to be consulted with conservationists as it would take several years to remove the monument protection.
In very bad condition
The Technical Road Administration (TRA) rated the bridge with grade five (the third worst on the scale), which means “bad condition”. Some of its parts got even one-grade worse rating, i.e., the sixth grade. Experts from the Klokner Institute conducted a series of analyses and wrote a list of bridge parts that required the most acute intervention.
Procedure for examining the condition of Hlávka Bridge
According to available sources (here and here), the bridge was fitted with sensors, and samples were taken for laboratory analysis. The following was examined:
- temperatures at different points of the bridge structure,
- deformation of selected bridge joints,
- samples of material from the bridge structure (to check the condition of the bridge in places that cannot be checked with just a glance),
According to prof. Ing. Jiří Kolísko, Ph.D. from the Klokner Institute, the main problem with the bridge was leaks that caused some concrete parts to fall off. In addition, there were transitional slabs between the new and historical parts and their condition was much worse than in the rest of the structure. “All this had an impact on the load-bearing properties of the bridge,” stated Kolísko.
Reconstruction of Hlávka Bridge
The article at tsk-praha.cz wrote about the process of the reconstruction of Hlávka Bridge as follows:
Dug and drilled probes into the roadway, pillars and subsoil were done on Hlávka Bridge, which also required temporary restrictions on car traffic on the bridge. These works took place in several stages in September and October 2018. “Dynamic stress tests were also carried out in November but they did not affect the traffic on the bridge. At the turn of the year, the static tests continued but due to their difficulty, they required temporary traffic restrictions,” added Petr Smolka, CEO of TRA.