Bridge designing will have to change, says expert

Maribor, 9 August - Marjan Pipenbaher, an internationally acclaimed construction engineer and bridge designer, believes climate change will have to be taken into account when planning transport infrastructure and rebuilding bridges that have been destroyed by the floods.

The only bridge that was not swept away by floods in Mežica, north.
Photo: STA

Due to the abnormal amount of rainfall torrential river flows in the latest floods exceeded the volumes determined in hydraulic studies. As a result many bridges collapsed, Pipenbaher has told the STA,

In some places, the river flows passed hundred-year water levels that determined the dimensions of the river bed and the bridge spans, he explained.

Another major problem was fallen trees and other debris swept along by the water, which then piled up in between supporting pillars and under the carriageway structures, which further obstructed the flow.

Taking into account these new circumstances, the hydraulic studies of rivers will have to be amended and construction adapted accordingly, he said.

When designing and building bridges across torrential rivers, building pillars in river beds will have to be avoided as much as possible, he said.

"Such construction will be somewhat more expensive, but the risks of reduced flow capacity and collapses will be significantly reduced," he believes.

Reconstructing bridges with spans of up to 10 metres takes between 14 days and three months. When it comes to bridges across torrential rivers, spanning 30 to 100 metres, as most Slovenian bridges are, it takes between one and six months, depending on how bad the damage. "Some bridges will have to be torn down and built anew," Pipenbaher said.

He trusts that reconstruction and renovation of the damaged bridges will be done properly. "Some temporary bridges may have to be built to set up essential links, but these will later be replaced by bridges of high quality construction."

Pipenbaher believes that Slovenia has enough bridge designers and builders, but says that the whole construction community will have to come together. Aid is also coming from abroad, in particular building machinery and pontoon bridges.

© STA, 2023