March the 28th, 2024 – We’ve been inundated with scenes from Baltimore recently after a vessel crashed into the Baltimore Key Bridge, resulting in the structure’s total collapse. Could the famed Pelješac Bridge withstand such an incident?
As Poslovni Dnevnik writes, the bridge in Baltimore that has been all over the news over the last few days was built back in 1977. It was 2.6 kilometres long and was considered a proverbial major artery for the area, with 11.5 million vehicles crossing it annually.
Gordana Hrelja Kovačević, a civil engineer, explained to HRT that it was a steel bridge, and the columns, as well as the foundations, were made from reinforced concrete.
“It’s being claimed that the bridge was designed according to all valid regulations. However, since 1977, ships have increased in size, the mass of those ships has also increased by as much as 50 percent in some cases. When designing a vessel, there are some very strict regulations that must be adhered to. We have valid European norms and rules, that is, Croatian norms and rules, which have been adopted from European norms. Among everything else, they define the size to which we have to dimension any bridge we’re designing,” she said.
could croatia’s Pelješac bridge withstand a strike from a 300-metre-long cargo vessel?
Hrelja Kovačević emphasised that there are no trials. Bridges being crashed into by vessels of varying sizes to test them out isn’t part of the standard tests. New bridges are instead only tested for traffic loads.
“Regarding the impact of a vessel on a bridge, there’s no actual testing for that. However, bridges do undergo a process called recalculation. The Pelješac Bridge also underwent this in regard to to the impact of a vessel. However, this wasn’t done for the impact of such a large vessel, only for a medium-sized ship of about a hundred metres in length,” she revealed
On the Pelješac Bridge, there are rubber, rotating bumpers placed on the pillars, which are located along the waterway, and vessel accidents like the one across the pond in the USA recently tend to occur when a ship deviates from that waterway.
A new bridge for baltimore in three years?
The disaster that happened on the bridge in Baltimore will have consequences for the American economy, because that bridge was an important bottleneck for the transportation of various goods, especially coal.
Gordana Hrelja Kovačević said that it is difficult to talk about the reconstruction of that bridge, and it’s more than likely that new bridge will be built. That construction process could take less than three years, as it will be deemed an emergency procedure.
Allegedly, the bridge in Baltimore had reinforced concrete load-bearing structures that simply did not withstand the ship’s impact, and they fell apart as if they were made of paper very quickly.
“Bridges should be regularly maintained”
The reconstruction of the bridges over the Sava River in Zagreb has started, but is the Krk Bridge, which was built in the early 1980s to connects the island of Krk and the mainland, also being renovated? Is there a shelf life for bridges, especially those that are used every single day throughout the year?
Hrelja Kovačević emphasised that the lifespan of the actual construction for normal bridges is about 50 years.
“For more important ones, it’s a hundred years, and it can be more than a hundred years sometimes. When the Pelješac Bridge was designed, all of the parametres were taken for durability of more than a hundred years,” she said. As for the maintenance itself, Hrelja Kovačević said that bridges should be maintained regularly. And reviewed frequently, according to any newly adopted regulations.
Zagreb’s bridges have started being properly restored, but they are not being strengthened.
