Adam Scheinherr (Praha sebo): We will extend the lifespan of Barrandďák to 100 years
photo: Rudolf Komár, PrahaIN.cz/Adam Scheinherr
POLITICS IN OWN WORDS Deputy Mayor m of Prague for Prague to himself on his Facebook on August 3 for the reconstruction of the Barrandovský bridge
The repair of the century continues and from Monday we go to three-shift operation – we work non-stop, day and night. But the last few weeks have been really turbulent on the construction site. Unexpected technical facts appeared, which unfortunately almost always happen with constructions of a similar scale. We can do our best to prepare, but the exact procedures of the bridge builders at the time are only revealed to us during the reconstruction work itself. I already wrote that we first discovered an unexpectedly thick asphalt layer on Barrandďák. In some places, up to twice as much as what would be important. In some places, the asphalt was up to 30 centimeters thick, and if we were to preserve such a robust layer, we would be putting unnecessary strain on it, and there would also be a risk of water caverns forming there.
Added another “surprise”. At the beginning of the 1980s, the builders of the bridge probably decided during construction that the most heavily loaded pillar at the connection to the Strakon ramp would be reinforced with steel reinforcement to a significantly higher extent than the project from that time indicated. We couldn’t know that. Today, these drilling of the pillars complicate things considerably. If we come across reinforcement that was not mentioned in the project, we have to look for another space where we can extend the ten-meter borehole.
Details about these two technical complications were gradually obtained these weeks as the builders progressed in the reconstruction. We asked experts from CTU and they proposed a unique technological solution for surfaces using high-strength concrete. This technology was first used only five years ago in America and is a great innovation. High-strength concrete can strengthen the structure and is waterproof at the same time. According to associate professor Vráblík from CTU, with whom I used to consult on the Barrandovský bridge, the overall lifespan of the bridge will be extended up to 100 years.
The new facts meant for me a decision between two options. The first was the best asphalt: let the surface be poured and finish the reconstruction by the beginning of September as planned on paper. The second option was to use the technical complications and have the surface reinforced with high-strength concrete, which will extend the life of the bridge up to 100 years, but at the cost of extending the construction by no more than 30 days (but hopefully less).
You probably understand which option I chose. It is a disaster for Prague that for years it was planned according to election periods and political will. Logically, such a huge project as the repair of the Barrand bridge never happened – it was always too soon before municipal, parliamentary or other elections. We have finally started, we are doing what is needed, we are choosing the best possible technologies, and if we continue to work after the elections, then always only like this.