Bay Bridge Officials Plan To Prevent Cracks

Toll bridge officials plan to take steps to prevent future eyebar failures on the east span of the Bay Bridge - like the one that closed the bridge twice in 2009 - and to prepare for a quick fix if another failure happens.

A committee of the Bay Area Toll Authority on Wednesday voted to pay bridge engineering firm T.Y. Lin $1 million to design a system of dampers that could be installed on the cantilever-style portion of the current east span to reduce the vibrations caused by wind and the relentless pounding of traffic.

T.Y. Lin, which analyzed the failure of the cracked eyebar discovered over Labor Day weekend last year, and Caltrans engineers determined that vibrations caused by wind led to both the initial failure of the eyebar, which is a key structural piece, as well as the collapse of the repair job that flung tons of steel to the bridge's upper deck in October.

The firm will also design, but not construct, a device that could be quickly fabricated and installed should another eyebar crack.

"We just want to be prudent," said Andrew Fremier, deputy executive director of the authority.

Fremier said thorough inspections of the eyebars have found a number of small pits or nicks in the metal that could be a precursor to cracking, but have been repaired by grinding and smoothing them out.

"It doesn't mean you will get a crack," he said, "but it means you could get a crack."

Fremier said he did not know the exact number of pits that had been found and fixed but said it was somewhere in the low double digits. Engineers from T.Y. Lin and Caltrans don't believe any further eyebar failures are likely, he said.