San Francisco, CA – Broken rods on the Bay Bridge are being investigated by Caltrans. Nearly three dozen of the threaded steel rods snapped as crews tightened down the fittings a few days ago.
The rods — nine to 16 feet long and as thick as a person’s thigh — are being used to connect the bridge deck to the 10-food concrete cap on the massive pier just east of the self-anchored suspension span tower.
The broken rods are part of the new eastern span of the Bay Bridge in San Francisco, which is set to open later this year. The Metropolitan Transportation Commission is overseeing the new $6.4 billion span construction along with the state.
Spokeesman Randy Rentschler stated late on Tuesday, “Caltrans is diagnosing the problem and we are confident they will find a solution.” Caltrans was expected to brief the commission in Oakland on Wednesday morning.
The new Bay Bridge’s broken rods are not considered a structural problem with the bridge. They will also not delay the span’s scheduled opening on Labor Day weekend. While they do not help the bridge’s structural integrity, the woven steal rods are part of the span’s seismic protection features.
The new bridge has been designed to remain passable for emergency and supply vehicles directly after a major earthquake. In total, there are 288 rods. So far, Rentschler stated, 96 of those rods have been tightened. About one third of them broke.
Rentschler added of the broken rods, “The bridge itself is well, well, way overdesigned. And this is a seismic element that is important, but Caltrans is confident that they have a design option to design around this.” It is possible that the snapped bolts had hydrogen in their metal, which caused them to be brittle.
Caltrans reportedly suspects that the hydrogen was part of a production problem during the steel galvanization process. Engineers added that the bolts were made in the United States. There is no word on how long it will take for the Bay Bridge’s broken steel rods to be replaced.
[Image via Wikimedia Commons]