FRIDAY, DECEMBER 20, 2013
A chorus of safety concerns by independent engineers has rapidly drowned out the fanfare over the recent opening of the new $6.4 billion San Francisco-Oakland Bay Bridge.
In a report endorsed by several experts, two California engineers are lambasting the state Toll Bridge Program Oversight Committee's analysis of engineering issues on anchor rods that are key for the bridge's seismic stability.
The 32 anchor rods, or bolts, were damaged in March when they popped loose days after crews tightened them. The anchor rods were originally installed in holes in the concrete caps in 2008, but these holes were left to fill with rainwater for five years before the bolts were tightened.
Despite a last-minute fix that allowed the state to reopen the bridge as scheduled on Labor Day, the new reports condemn the work of the Toll Bridge panel, saying it lacks expertise and calling its work "woefully inadequate."
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| Baybridgeinfo.org / Courtesy of John Bors, Chemco Systems |
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Two California engineers have released reports calling Caltrans analysis of Bay Bridge project problems "woefully inadequate." |
TBPOC, comprised of representatives from the California Department of Transportation, the California Transportation Committee, and the Bay Area Toll Authority, has managed the construction of the new Bay Bridge since 2005.
Anchor Rod Problems
The damning report was authored by Yun Chung, an 81-year-old retired materials engineer who worked for Bechtel Corp.; and Lisa K. Thomas, P.E., a metallurgical and materials engineer for Berkeley Research Company, a California consulting engineering, laboratory and field testing concern.
Their 105-page report, "High Strength Steel Anchor Rod Problems on the New Bay Bridge," was published Nov. 12, with a few revisions to the original report, which was issued Oct. 28.
The report was also reviewed by a professor of civil and environmental engineering at the University of California, Berkeley; the president and mechanical engineer at Berkeley Research Company; a retired chief materials engineer; a lead materials engineer; and a professor of materials engineering at San Jose State University—all of whom concurred with the report's recommendations, the report said.
'Bring Down Entire Bridge'
Chung and Thomas also recently released an 18-page supplementary report after The Sacramento Bee requested more details about their concerns.
"Main Concerns About Anchor Rods on the New Bay Bridge" specifically focuses on the anchor rods for the main cable and the tower base, some of which could be more susceptible to hydrogen embrittlement cracking than any of the other rods on the bridge—even the 740 that are going to be replaced, according to the report.
If these anchor rods fail, it could "bring down the entire [self-anchored suspension] bridge," the authors say.
'Some 200 Errors'
In July, the toll bridge committee released its 130-page "Report on the A354 Grade BD High-Strength Steel Rods on the New East Span of the San Francisco-Oakland Bay Bridge With Findings and Decisions," detailing its investigation into why the bolts failed and who was responsible, a chronology of events, and an approved fix for the problem.
The authors say the state's report has "some 200 errors and technically questionable or erroneous statements" and call the committee's new supplementary requirements for replacement anchor rods "ineffective."
These alleged errors range from typographical to wrong conclusions about the cause of the anchor rod failures.
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| Caltrans |
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Anchor rods, or bolts, are key for the bridge's seismic stability. After sitting in water for five years, the rods were tightened in March, and 32 popped loose days later. |
According to the committee, initial testing showed that hydrogen was to blame, but layers of other problems dating back several years point to a series of missteps that could have prevented the problem earlier.
"Hydrogen is one of those things that works its way in in ways that you don't always typically see. And that's why hydrogen is an issue when you're dealing with steel. Even with the most rigorous inspection practices, hydrogen somehow sneaks its way in and manifests itself in situations like this," Tony Anziano, Caltrans Toll Bridge Program Manager, explained in March.
Chung and Thomas call the agencies' understanding of hydrogen embrittlement susceptibility "woefully inadequate" and say that Caltrans needs "meaningful reform ... before they are allowed to take on another mega-project for the State of California."
By failing to properly protect the bolts as they sat in pools of water for five years, the hydrogen that caused the failures came from the corrosion of the bottom of the threads, Chung and Thomas say, adding: "Their conclusions as to the cause of the shear key anchor rod failures were wrong."
Disputing Caltrans
"The July 8, 2013, TBPOC report on the new Bay Bridge anchor rod problems has all the characteristics of an un-reviewed or unedited draft or rough notes from which a more refined, comprehensive document was to be constructed.
"As issued, it cannot be considered a definitive professional engineering report intended to provide remedial 'resolutions' for what was clearly a major materials engineering failure on a $6.4 billion project. TBPOC-Caltrans need to do more work, a lot more work, and present a new revised report on the anchor rod problems on the new Bay Bridge," the authors wrote.
All of the 32 anchor rod failures occurred in the bottom threads, but TBPOC doesn't investigate that commonality in its report, the authors say.
"Not only did the TBPOC fail to explain this most peculiar failure pattern but also completely ignored the significance of this failure," Chung and Thomas wrote.
By ignoring this failure pattern, the TBPOC team incorrectly concluded the cause of the failures as short-term hydrogen embrittlement or internal hydrogen embrittlement, according to the report.
Equally alarming, the authors say, is that the Federal Highway Administration approved the committee's investigation into the bad bolts.
"A series of events since then have revealed a serious weakness in materials engineering expertise not only at Caltrans and its contractors but also in other government agencies," Chung and Thomas wrote.
Caltrans engineers ordered tests on the bolts in 2008, but those tests were never done after contractor American Bridge/Fluor disputed whether they were required. In April, Caltrans released hundreds of pages of documents that showed its inspectors found structural integrity issues with some of the bolts years ago.
Caltrans accepted the bolts because the agency believed the hydrogen had been eliminated from the galvanizing process, Anziano said.
Long-Term Issues
Chung and Thomas say their report was necessary because TBPOC and Caltrans "have been oblivious to the metallurgical conditions unique to these anchor rods" and need to understand the unique metallurgical characteristics of the rods that could "adversely affect" hydrogen embrittlement susceptibility.
In fact, the authors say that the troop of engineers who prepared the July report are not even aware of some of the long-term metallurgical issues the anchor rods face, because the stress corrosion cracking tests they used "completely missed the mark in connection with the validity of their remedial resolutions."
The anchor rods for the main cable include 55 rods with cut threads and 217 rods with rolled threads, formed by cold rolling of steel bars that were heat treated to high hardness. According to the authors, this rolling operation altered the microstructure by increasing the metal hardness of the surface layer, the area reaching about 0.1- to 0.15-inch-deep.
However, Caltrans used a test protocol that required the first hardness indentation to be made at 0.25 inch from the surface on the rods with rolled threads, which resulted in little difference in the hardness distributions between rods with rolled threads and those with cut threads.
In reality, the authors say, the difference could be greater in the surface hardness between the two types of rods, thus increasing cracking susceptibility.
Requesting a New Report
Chung and Thomas have recommended that the California Senate's Transportation and Housing Committee reject the July report from TBPOC and Caltrans "as an unacceptable public document" and request that a new report be issued.
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| Flickr / sirgious |
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California legislators are investigating the problems on the Bay Bridge project and how to improve Caltrans management, as well as problems that impact all megaprojects.   |
State Sen. Mark DeSaulnier (D-Concord), chairman of the Senate Transportation and Housing Committee, told The Sacramento Bee that the report added to the urgency of a full, independent review of construction concerns involving the span.
He said he would ask University of California experts to review Thomas and Chung's report.
Chung said he sent his report to Steve Heminger, executive director of the Bay Area Toll Authority and chairman of the bridge oversight committee, The Sacramento Bee reported. Heminger said he was reviewing the report and would eventually release a public statement.
Legislation, Investigation Focus on Caltrans
Caltrans' accountability is already the focus of several new pieces of legislation in the state.
Senate Bill 486, Department of Transportation: Performance Measurement Benchmarks, first introduced by DeSaulnier in February, would require Caltrans to identify performance measurement benchmarks and issue reports measuring the department's success in meeting these benchmarks.
The bill was moved to the inactive file Sept. 10, meaning that it is ready for floor consideration but is dormant.
DeSaulnier announced in October that he would lead an investigation into the issues on the Bay Bridge project, as well as chair a series of Senate Transportation and Housing Committee hearings to look at problems that impact all megaprojects and improvements that can be made by Caltrans management.
The committee will report on its findings, which DeSaulnier said he expects to "inspire reform measures."
"Creating legislation that creates greater accountability at Caltrans, and improves the management of future projects, will be a top priority of mine during the 2014 legislative session," DeSaulnier said.
On Sept. 6, Gov. Jerry Brown signed Senate Bill 425, The Public Works Project Peer Review Act of 2013, legislation that set standards for developing peer review groups for public works projects.
DeSaulnier, who wrote the bill, said, "Reviews should meet clear criteria before projects are touted as 'peer reviewed.' Common-sense reform measures such as SB 425 will help change the culture at public agencies, particularly Caltrans.
"I look forward to continue working with Gov. Brown and his administration to restore the public's trust in Caltrans," DeSaulnier said.
Bipartisan Support
Also on board with Caltrans reform is state Sen. Anthony Cannella (R-Ceres), an engineer who provided testimony to the Transportation and Housing Committee during the Nov. 13 informational hearing, "How to Save the State Billions: Improving Megaproject Outcomes."
"It is important that we rise above partisanship and work together to craft an approach that avoids the kinds of mistakes that we are examining today so we can rebuild the credibility of Caltrans in the eyes of the public," Cannella said.
"I want to be able to learn from the mistakes on the Bay Bridge and work to implement the lessons learned on the development of any future megaprojects."
After earlier reports that American Bridge/Fluor could possibly receive a $20 million bonus for delivering the project on time, despite the contractor's role in the bad bolts debacle, Cannella said, "The news that the 11th-hour decision to open the Bay Bridge will result in a $20 million bonus warrants an investigation.
"I am working with my colleagues in the legislature to ensure that this decision to use a last-minute temporary fix is completely investigated. ... As an engineer, I continue to be baffled by the decisions made in the building of this bridge."
Tagged categories: Bridges; Contractors; Corrosion; Department of Transportation (DOT); Federal Highway Administration (FHWA); Galvanized steel; Program/Project Management; Retrofits
