The preliminary findings of an investigation into cracked beams that forced the indefinite closure of the Transbay Transit Center are set to be released this week, including lab tests of metal samples.
The findings, which will be announced Thursday at a Transbay Joint Powers Authority meeting, are expected to include metallurgical lab test results of samples from a cracked beam over Fremont Street, the discovery of which led to the center’s abrupt closure in September, as well as a proposed repair plan. A smaller crack was also discovered in a second parallel beam.
The tests will clarify whether the quality of the steel contributed to the cracking.
But they are not expected to answer the question of when the facility will reopen, officials said.
Dennis Turchon, senior construction manager of the project for the TJPA, said that the findings are expected to explain what happened, but may leave unanswered questions that are likely to be presented next month.
“It’s going to talk to what happened. The what,” Turchon said. “Not so much the why.”
Turchon said that they will use the preliminary findings to determine possible repair work for an area over First Street, which has a similar beam but no cracks, and to develop a plan for the review of the entire facility.
“First Street is still getting confirmed what is needed,” he said. “Now with the preliminary findings of what happened you can look at the rest of the structure, the entire Transit Center to determine what else do you need to look at. That now can start being developed.”
The $2.2 billion Transbay Transit Center was closed abruptly in late September, around six weeks after its opening, when cracks in key steel beams were discovered. Since then, in further inspection of the facility “additional fissures have not been found,” according to a Dec. 7 memo from Eric Cordoba, the Transportation Authority Board’s deputy director for capital projects.
San Francisco has assembled a peer review panel of engineers under the Metropolitan Transportation Commission to review the findings and approve next steps. The panel was established at the request of Mayors London Breed and Libby Schaaf.
The San Francisco County Transportation Authority board, which is made up of the 11 members of the Board of Supervisors, were briefed Tuesday on the investigation, but no details were made public.
Supervisor Aaron Peskin, chair of the SFCTA board, called the issue “depressing.”
“The big question here is when and the answer is we don’t know,” Peskin said.
A final report on the “the root cause assessment is anticipated by early January 2019,” Cordoba’s memo states.
When the repair work can be completed and the facility reopen depends largely on how long it will take to procure steel.
The transit center was built through a joint venture between Webcor Builders and Obayashi Corp. Once a planned second phase is completed, the facility is expected to serve as the terminus for both Caltrain and the proposed California high-speed rail project connecting San Francisco to Los Angeles.
However the SFCTA has withheld funding from planning efforts for Phase II, pending increased oversight, including assembling an outside panel of experts to review the plans. “We anticipate completing the selection of panel experts by January 4, 2019 and completing the effort by May 2019,” said Cordoba’s memo. Transit