Norwegian highways authority Statens Vegvesen has temporarily closed three timber bridges as a precaution following the collapse of a new bridge in Sjoa on 17 February. Three bridges in Akershus have been closed after the authority said that an error in the design calculations had been identified as the reason for the collapse last week. Seven others have also been examined in the wake of the incident.
The highways authority said that following the Sjoa incident it initiated a comprehensive examination of other timber bridges in the region. "In discussion with the consulting firm Sweco Norway we have become aware that they have discovered an error in the calculation of Sundby road bridge in Dal in Akershus," said Statens Vegvesen deputy director Nils Audun Karbo.
"This bridge was erected in 2011. We have conducted a visual inspection of the bridge, and based on our own inspections and information from, among others, consultancy Sweco we have decided to close the bridge temporarily," he explained.
As a precaution the authority has also decided to close two other wooden bridges in Akershus, both of which carry private roads. These two have a similar design to the bridge at Sjoa and the highways authority intends to carry out additional calculations of the load carrying capacity of these three bridges.
"It is still too early to say exactly what the error in the calculation of Sundby road means for the carrying capacity of the bridge. Until we have more facts, we have chosen to close the bridge temporarily," said Karbo.
Statens Vegvesen has also decided to investigate seven wooden bridges in eastern Norway.These are also wooden truss bridges, but with a different technical solution to the bridge at Sjoa.
"So far, there is no indication that there are problems with these wooden bridges. But to be on the safe side, we have chosen to conduct a thorough review of these bridges," said bridge section division manager of the eastern region, Jon Henning Prestegarden.
