The director of the California Department of Transportation said Tuesday he would consult with independent experts from outside his agency about testing and construction concerns involving the foundation of the new San Francisco-Oakland Bay Bridge.
Malcolm Dougherty's comments reversed his agency's prior position and followed a Bee investigation on Sunday in which outside experts said apparent flaws in construction and testing called into question how effectively the bridge might withstand an extreme earthquake.
Those experts challenged conclusions reached by Caltrans and its engineering advisers.
In an interview, Dougherty said his agency's peer review engineers were the "premier experts" in the field, but conceded that "there's an impression that they are not impartial."
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He said his department would consult with "third-party" independent experts "to reassure people about the safety of the Bay Bridge." He didn't elaborate further.
The chairman of the California Senate Transportation and Housing Committee also called for an independent review of the foundation of the new Bay Bridge.
Sen. Mark DeSaulnier, D-Concord, said Tuesday his committee will hold hearings this summer in response to concerns raised in recent Bee investigations about the piles that underpin the span's signature tower.
"We need to make sure the bridge is safe before we open it," DeSaulnier said. "It's supposed to be a world-class bridge. It should have world-class oversight."
The agency expects to open the new, $6.5 billion span on Labor Day weekend 2013, to an estimated 100 million vehicles annually.
On Sunday, The Bee revealed that a builder of the new eastern span failed to disclose tests showing a large section of poor or soft concrete in the foundation.
Spokesmen for Gov. Jerry Brown and acting Secretary of Business, Transportation and Housing Brian P. Kelly referred all questions about the bridge testing and oversight to Caltrans.
Dougherty said the foundation piles were "built as designed and are sound and safe."
Recent Bee investigations have shown that many assertions concerning the safety of the bridge and the adequacy of its testing, made by Caltrans and its expert panel of engineers, were contradicted by agency documents. Ethics experts said financial and professional conflicts of interest compromised the credibility of findings by the Toll Bridge Seismic Safety Peer Review Panel, which said the bridge was well-tested and safe.
Steven Heminger, who heads the Metropolitan Transportation Commission for the nine Bay Area counties, defended the judgments of the peer-review experts. As chair of the state Toll Bridge Program Oversight Committee, he manages funds for Bay Area bridges and has been involved in developing the new Bay Bridge.
Heminger acknowledged that The Bee stories "are raising some serious questions."
"It's clear that the evidence is not completely unequivocal from every test done from every angle. But what we have on the balance of the evidence is very strong test results" for a design that builds in an extra margin of safety, he said, leading "to the conclusion that we've reached: We have a safe structure."
DeSaulnier said a "race against time" to complete the project before a massive quake hits the area has produced a "continuing failure to focus on safety."
"I do not understand why Caltrans has not been more forthright" said Sen. Ted Gaines, R-Rocklin, vice chairman of the Transportation Committee. "The public demands that we get to the bottom of this."
Both senators said that safety concerns warrant a fresh look by independent experts.
DeSaulnier said he agreed with experts contacted by The Bee who proposed computer modeling of how the tower foundation would respond in a worst-case simulation. If warranted by computer-generated scenarios, he said, physical examinations of the piles also might be undertaken.
Heminger also said he would consider computer modeling.
"I'm willing to discuss that with my colleagues on the Toll Bridge Program Oversight Committee," which includes Dougherty, he said.
Heminger added that he remains wary of endless testing and evaluation: "My concern is finding a way to get to taking 'yes' for an answer."
Dougherty said he did not favor such modeling because he does not see evidence of defects in the piles. But if independent experts recommend computer modeling after analysis of the engineering and construction record, Dougherty said, he'd be open to the suggestion as part of "further analysis or mitigation."