Researchers at the Vienna University of Technology (TU Wien) have completed work on a new kind of bridge that’s modeled to ‘open’ and ‘close’ like an umbrella.
The bridge is roughly 236 feel long and spans a small stretch of the Lafnitz River on the border of Austria and Hungary, where Austria’s new S7 motorway is being constructed.
Unlike most other bridge construction projects, the Lafnitz River bridge was assembled vertically instead of horizontally, and then lowered with bendable hydraulic joints that mimic an umbrella’s internal frame.
The two girders are connected to each other at the top, directly above the pier, ‘designer Johann Kollegger told the University news blog.
‘With hydraulic systems, this joint is then slowly lowered, and the girders unfold to both sides.’
The fact that the bridge can be assembled in a central location before expanding to span its full length could make construction much safer in the often dangerous terrain that require bridges, including steep mountainsides and across deep ravines.
‘Erecting bridges using scaffolding usually takes months,’ Kollegger said.
‘The elements for the balanced lowering method, on the other hand, can be set up in two to three days, and the lowering process takes around three hours.’
The project was backed by ASFiNAG, a public corporation operated by the Austrian government that builds and maintains the country’s freeways.
‘With this innovative construction method, we were able to meet both of our requirements for this sensitive area,’ ASFiNAG’s Berhard Streit said.



‘We are therefore very happy about the successful cooperation with TU Wien.’
Kollegger hopes his new method could one day become one of the standard approaches to bridge construction around the world.
‘Now that we have proven that the method is well-engineered and works perfectly,’ he said, ‘we hope that it will prevail and will soon become one of the common bridge building methods that are used around the globe and that the S7 Motorway will become an international pioneer.’
Source: Dailymail