Federal lab offers to test Bay Bridge rods

Rods like this are being tested by Caltrans, but some people are skeptical about the agency's reliability. Rods like this are being tested by Caltrans, but some people are skeptical about the agency's reliability. Photo: Carlos Avila Gonzalez, The Chronicle Buy photo Photo: Carlos Avila Gonzalez, The Chronicle Image 1 of / 20 Caption Close Federal lab offers to test Bay Bridge rods 1 / 20 Back to Gallery

With critics voicing skepticism about the reliability of Caltrans' testing of steel rods on the new Bay Bridge eastern span, a federal laboratory offered Wednesday to do some of the checks for free.

Critics have faulted the $10 million testing program that Caltrans began for the 2,200 galvanized, high-strength rods and bolts on the span after 32 rods on a seismic stability structure failed last year.

Yun Chung, a former Bechtel engineer, said at a hearing that Caltrans convened with scientists Wednesday that the agency has never determined what caused those rods to fail - whether something went wrong while they were being made, or whether they were damaged when they were exposed to the bay environment.

As a result, he said, the agency cannot draw scientific conclusions about whether the remaining steel fasteners are at risk.

"Can I trust what Caltrans has been doing?" he asked. "Caltrans really needs to find out what is happening here."

The National Institute of Standards and Technology is offering to perform tests to settle the key question of what caused the problem, according to a letter cited by Chung's research colleague, Berkeley metallurgist Lisa Thomas.

Caltrans officials expressed interest in the offer, which Thomas said was "worth a shot."

The test will try to determine whether steel-cracking hydrogen invaded the rods in the environment or was left behind after manufacturing. If it happened on the bridge, she said, that would call into question the long-term reliability of many of the span's fasteners.

"We want to make sure (we have) as much understanding of the metallurgy as we possibly can," Caltrans Director Malcolm Dougherty said in opening Wednesday's session in Oakland. He said the rods and bolts are being subjected to a "very exhaustive testing program."

The 32 rods that broke on the seismic-stability structure when they were tightened had been sitting in rainwater on and off for five years.

Caltrans said this week that the first batch of rods it tested broke when they were tensioned below their maximum capacity, but above the level at which they are in service on the bridge. A more recent batch survived tensioning above their maximum rated levels, Caltrans said.

The rods and bolts are among several issues Caltrans is dealing with on the $6.4 billion eastern span. It has also been forced to answer questions about whether water leaks threaten steel support structures on the suspension portion of the bridge.

Gov. Jerry Brown, who appointed Dougherty to head Caltrans in 2012, said Wednesday that the rod- and bolt-testing program is "proving reasonably well. You can be sure since I cross the bridge on a regular basis, that I take whatever steps are necessary to keep it in place."

Asked whether any officials would be held accountable for bridge problems, Brown said, "If somebody did something wrong. But remember, this thing's been going on for years, and all sorts of questions have been raised. And I have to judiciously evaluate them and not jump just because somebody has written a few stories."