SACRAMENTO -- A builder of the new Bay Bridge failed to disclose that a 19-foot section of concrete in the foundation of the span's signature tower had not hardened before it was tested. By keeping quiet about the problem, the builder prevented further examination or repair.
The Sacramento Bee found descriptions of the apparent defect in records provided by Caltrans last fall to reassure the public about the overall stability of the suspension segment of the bridge's eastern span. Experts said the problem, combined with other construction and testing lapses by the California Transportation Department and its contractors, raises new questions about the structural integrity of the bridge.
Kiewit-FCI-Manson, a joint venture, built the foundation as part of a $177 million contract. It did not provide the problematic 2007 test results until after a Bee investigation in November showed that a Caltrans employee skipped required test preparation for separate checks of the same foundation and fabricated results on other structures.
The agency plans to open the $6.5 billion structure, the costliest public-works project in state history, by Labor Day 2013 to an estimated 100 million drivers annually. Caltrans said the bridge is sound and can withstand any anticipated earthquake.
Beyond the large area of suspicious concrete in one of the reinforced underground foundation piles, a Bee
Among the findings:
Larry Olson, president of Olson Engineering, which conducted the sonic tests, declined to comment without permission from Kiewit Corp. Kiewit referred all questions to Caltrans.
Olson Engineering detected the problem concrete in Pile 3 in 2007, calling it "a batch of concrete that has not fully set at the time of testing" or "a very poor area of concrete."
"The most likely cause for the (19-foot) anomaly is concrete that didn't cure," or harden, said Les Chernauskas, general manager of Geosciences Testing and Research Inc., a Massachusetts company that specializes in sonic testing.
Through a spokeswoman, Gov. Jerry Brown declined to answer questions about whether Caltrans has kept his office informed of ongoing concerns about the bridge.
Caltrans spokeswoman Tamie McGowen responded in writing to Bee questions. "Substantial evidence," including tests of the small mock-ups and the other bridge piles, indicates that the abnormal concrete in Pile 3 eventually hardened properly, she wrote.
"We are confident in the structural integrity of the main tower foundation and that the bridge will perform as designed to handle an extreme earthquake," McGowen said. A panel of engineering experts hired by the agency to re-evaluate the safety of the foundation concurred.
"The way that they conducted the testing program, and the results, do raise some serious issues with respect to the quality of the concrete," said a university professor and expert in deep foundation testing, who also reviewed the documents at The Bee's request. He spoke anonymously for fear of jeopardizing business relationships with contractors for Caltrans, among the nation's largest public-works funders.
A chief concern, he said, involves the absence of sonic data for Pile 8 and the location of problem concrete in Pile 3, toward the top of the pile, "subject to the most significant loads during an earthquake."
Kiewit began building foundations for the Benicia Bridge shortly before taking on the Bay Bridge project. Records show that Caltrans engineers recommended rejection of nearly all the Benicia piles built before awarding the Bay Bridge contract to the Kiewit joint venture. Those piles, almost one-third of the Benicia job, were deemed either too flawed for use without repair or required retesting due to construction errors.
Soon after the Bay Bridge sonic testing, Kiewit-FCI-Manson provided Caltrans with results for six of the 13 piles.
They showed only minor problems. It failed to deliver the other sonic reports, including one showing the huge anomaly.
Caltrans did not request those tests, McGowen said, which technically were not required by the construction contract.
Because the company declined to comment, its motives for withholding test data remain private. Substantial repairs on a giant pile can cost up to $1 million.
Thomas W. Joo, a University of California, Davis law professor and contract authority, said that even if Kiewit and its partners had no contractual duty to report the sonic data, they could face legal liability for "straight-up bad faith."
"If it's a matter of public safety, the calculus is different," he said. "The whole thing is colored by what's at stake."
By providing findings for six piles, the builders could have "engendered a duty to disclose" more fully, Joo said. "Partial, misleading disclosure is a species of fraud."