Prototype Fix Installed on Wind-Damaged Sabo Bridge
The Sabo bike and pedestrian bridge is back open Friday after a week of repairs.
A prototype fix was installed on the Sabo pedestrian bridge in Minneapolis Thursday that engineers hope will lessen cable vibrations like the ones that caused enough stress to crack and fracture crucial steel plates on the structure in February.
"We want the public," explained Brian Santosuosso, a senior associate with consultant Wiss, Janney, Elstner Associates, "to feel like we don't have vibrating cables."
Santosuosso's firm was hired by the city of Minneapolis and Hennepin county to investigate the fracturing of two of the bridge's diaphragm plates and to design a solution to ensure future wind vibrations won't cause further damage to the iconic walkway, which is elevated over busy Hiawatha Avenue.
During and shortly after construction, bridge designer URS Corp decided not to install a damping system on the bridge that Santosuosso believes would have mitigated some or all of the vibrations.
When asked whether a damping system, which can act essentially as shock absorbers, would have prevented the damage to the bridge had it been installed when the bridge was built, Santosuosso answered, "If we didn't have vibrations in the cables, then we wouldn't have had the cracking."
"The stresses would have been less, so therefore the cracking would have been less or it wouldn't have happened," he said.
"If (a municipality) wanted to be totally confident that the vibration of the cables had been eliminated, they would have to install a damping system," Santosuosso told 5 EYEWITNESS NEWS in his first on camera interview since his company's investigative report was released at the end of June.
Watch our story above to watch crews install the prototype and see the size of the template plate.