Feds to send hunks of bridge to lab for testing

0 Comments | Oakland Tribune, Apr 21, 2005 | by Sean Holstege, STAFF WRITER

Federal inspectors plan to remove, by week's end, pieces of steel in the new Bay Bridge to test if welds are safe by pouring acid on the samples in a laboratory.

Inspectors began visually and magnetically testing welds in the foundations of the new bridge after being flown in from New York and Washington state by the Federal Highway Administration.

"The removed welds will be tested in an independent lab, where sections will be sliced, chemically treated and then examined. This process will give a deep read into the quality of the weld. It will answer any questions regarding whether the weld is good or not," Caltrans said in a statement Wednesday.

The metal will be taken to Washington, where a lab at Jay Dwight Co. will examine it, Caltrans spokesman Mark DeSio said.

Caltrans bridge engineer Dan McElhinney said federal inspectors will remove large pieces of steel. Some could be as large as an entire 5½-foot vertical weld and its surrounding steel.

Caltrans would not disclose the exact number or location of the steel sections that will be removed because FBI agents are directing the tests. McElhinney said random samples may be removed in addition to the specific areas of interest to the FBI.

The FBI and state Attorney General Bill Lockyer launched criminal and civil investigations after numerous current and former bridge welders alleged they covered over defects to keep pace with heavy production demands.

Caltrans and prime bridge contractor KFM Joint Venture have maintained the allegations are baseless.

William Ibbs, a University of California, Berkeley, civil engineering professor, said the proposed "destructive testing" is the most rigorous exam possible.

"It's sounds on the up-and-up. I can sleep well at night," he said.

"Think of a weld as an onion," he explained. "You've got multiple layers and the thing that holds the onion together are the most inner layers. A flaw on the inner layer is more serious than a flaw on the outer layer."

A visual or particle inspection might miss internal flaws, he said. The destructive testing -- as long as an appropriate sample of welds is chosen -- will provide the reliability people want.

Ibbs suggested that investigators might also conduct a fatigue test, using repetitive motions perhaps, much like bending a paper clip 10 times to see if it will snap.

KFM said the welding scandal has cost $80,000 a day since Caltrans Director Will Kempton ordered a halt to welding on April 7. McElhinney said it may be two to three weeks before results from the lab tests are known.

Staff writer Jill Tucker contributed to this report.