Fixing a batch of broken bolts on the new Bay Bridge could cost up to
$10 million, but it’s still unknown if that work will affect the opening date — and it’s likely Gov. Jerry Brown will make the call on when the structure is ready for traffic.
Bridge officials have decided that a saddle design is the best retrofit solution for a segment of the new $6 billion span that is seismically vulnerable due to the discovery of cracked steel rods. The rods act as bolts to stabilize the bridge’s pier towers with its road deck, but they’ve been deemed useless because of cracks caused by a phenomenon called hydrogen embrittlement.
The saddle will be placed on top of the bolts and connected to steel cables that are post-tensioned and covered in additional concrete elements, according to Andre Boutros, executive director of the California Transportation Commission and member of the oversight group managing the repair project. The saddles will cost between $5 million and $10 million. Bridge officials are still determining how that cost will be covered between tax revenue and the private manufacturer who
provided the broken steel bolts.
Boutros said the retrofit work should be completed by the bridge’s scheduled opening date of Labor Day weekend. However, officials did not guarantee that date, mainly because they’re still conducting tests on a separate batch of bolts, manufactured in the same manner as the broken ones.
There are about 1,200 bolts of varying types on the new span. Caltrans, the state transportation department that owns the bridge, is currently performing a variety of reviews on those bolts. Those include destructive tests, where the steel structures are twisted to their breaking points in off-site laboratories. So far, the bolts have shown no signs of hydrogen embrittlement like the others.
Additionally, the bolts are undergoing another set of “wet tests,” designed to determine their ability to withstand corrosion. Caltrans also asked the Federal Highway Administration to conduct a separate independent review on the sufficiency of the steel.
The results of those tests and reviews are likely to be released at a special May 29 committee meeting of the Metropolitan Transportation Commission, the regional group that oversees the span. Officials will have to decide if — and when — it’s
necessary to remove those bolts.
Steve Heminger, executive director of the MTC, said bridge officials will have to weigh the pros and cons of allowing traffic to remain on the old Bay Bridge, a span that has proven to be seismically insufficient.
In comments to reporters on Tuesday, Brown said that he believed the public still had confidence in the Bay Bridge. He said the broken bolts weren’t setbacks, but a common example of what can happen in major infrastructure projects.