Cracks found in Bay Bridge construction

January 26, 2009 7:01:44 PM PST
The new eastern span of the Bay Bridge will be safe and on time says Caltrans, despite problems with some welding. Cracked welds were found in steel sections being made in China, but Caltrans though says it has fixed them.

Giant steel pieces of the new Bay Bridge roadway are being made in China. They'll sit beneath the soaring single tower just east of Yerba Buena Island.

MacTec engineering and consulting was hired to inspect the steel. Last year it told Caltrans there were too many cracked welds. Published reports show a MacTec inspector complained Caltrans had made his role in China one of "Collecting and analyzing data to justify decisions to move the project forward despite not being in compliance."

"There is absolutely no safety risk at all here. What this was potentially was a maintenance item," says Bart Ney, from Caltrans.

Caltrans says the cracks were in tack welds. Those are just the preliminary welds holding pieces until the more sturdy welds go in. Ultimately the steel structure doesn't count on those tack welds to hold it together.

Caltrans had a professor in Pennsylvania study if the cracks might spread. He concluded that the worst-case scenario would have been some inconvenience down the road.

"We could have had vibrations cause damage to the inside of that deck portion and we could have had to close the lanes, 20 years from now, one at a time to do welding on the inside of the bridge. That's the worst-case scenario which will not come to pass because we did the fix," says Ney.

"Tack welds should not crack, to start with. There's no reason for tack welds to crack," says Abolhassan Astaneh-Asl, from UC Berkeley.

UC Berkeley civil engineering professor Astaneh-Asl says he's alarmed by repaired welds, and thinks Caltrans needs to explain more.

"It is important for Caltrans to publish why the tack welds cracked, if that's the case, complete full review if there was one, and why reviewer felt this cracks not important," says Astaneh-Asl.

In 2005, a federal investigation of possibly faulty welding on another part of the new bridge found nothing.

THE BACK STORY: Bridge inspection firm now replaced


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