SAN FRANCISCO (KCBS/AP) -- Crews continue to work on the damaged Bay Bridge's eastern span Thursday morning, with Caltrans officials cautiously optimistic that they can complete their repair work by midday on Thursday. Once the work is done, Caltrans says testing will take at least three more hours before a decision can be made about re-opening the bridge.
KCBS Team Coverage: Bridge Repair
"Once all the steel's in place, testing is the next critical element and the tensioning of those rods has to be done very carefully and the shortest amount of time that that tensioning can take is approximately three hours," Caltrans spokesman Bart Ney said.
Caltrans has asked a team of federal and independent engineers to inspect the repair work once it's completed.
Crews working for Caltrans contractor MCM Construction are involved in a variety of tasks, including cutting, drilling, and welding steel to replace the failed parts that crashed to the bridge's upper deck Tuesday afternoon. Those pieces were part of a repair carried out on Labor Day weekend to fix a broken element known as an eyebar.
KCBS' Margie Shafer Reports
Three cars were damaged, and one person suffered minor injuries when the metal debris fell onto the heavily used span during rush hour Tuesday.
Traffic was jammed Wednesday on other highways, as motorists looked for alternatives to the bridge, which carries about 280,000 cars each day. KCBS traffic reporters saw indications that Thursday would bring more of the same, with hgiher-than-usual traffic volume as early as 4:30 AM on many Bay Area freeways.
Public transit agencies scrambled to deal with a massive influx of new riders. Transbay ferry systems added runs and used larger boats, while BART reported record ridership. BART's Wednesday passenger count surpased 500,000, easily topping the previous daily rider record of 405.000.
During the morning commute period on Wednesday, "BART ridership was up nearly 50 percent transbay," said BART spokesman Linton Johnson. "That's a total of 83,000 transbay riders."
Johnson says a normal Wednesday morning would see about 55,800 riders. He adds that parking at BART stations is an issue and would encourage people taking BART not to drive and park at stations.
Even the NBA's Houston Rockets became public transit converts, riding a ferry from San Francisco to Oakland for Wednesday night's game against the Warriors at the Oracle Arena. It's the first time Warriors management can recall a visiting team using the waterways to cross the Bay.
The Bay Bridge closure seems to have lead to increased traffic congestion in San Francisco, with Judson True of the San Francisco MTA saying that parking control officers have been helping direct heavier than usual traffic in areas like the Marina and South of Market.
KCBS Team Coverage: Alternative Options
"I think it's really about more cars using some of the approaches into the city, and off-ramps than would normally be the case, so we are seeing some congestion in those locations," said True.
More cars also used the Golden Gate Bridge on Wednesday morning, but spokesman Mary Currie says there was only a moderate increase on the district's ferry service.
"On the first three departures we had about 50 to 60 additional people, and then we ran one additional vessel with 72 additional people," said Currie.
Many commuters are eager to get back behind the wheel, provided it’s safe to do so.
”Lets make sure we check all the eyebeams at this point. I don’t want to go back over the bridge at this point, if pieces are falling down onto my Mazda,” said one BART rider.
Commuters can also go to 511.org for more information on commuter options.
What Went Wrong?
Federal officials are sending engineers to find out what caused a repair on the Bay Bridge to fail and send a 5,000-pound crossbeam and two rods into rush-hour traffic.
Federal Highway Administration spokeswoman Nancy Singer says the agency did not inspect the original Labor Day weekend repair, relying only on state inspection reports.
The pieces that broke Tuesday evening were part of major repairs done after crews discovered a cracked link during an earthquake safety upgrade.
Ed Pucci with repair contractor MCM Construction of Sacramento believes wind and traffic vibrations caused fatigue to one of four tension bars that had been installed over the cracked eyebar, causing it to fail.
”We’re using new materials, with a design change. It’s a ball and socket type of thing, as opposed to flat on flat,” said Pucci. “They believe that what might of happened because of the winds and vibrations on the bridge, that with the flat on flat there was some fraying of the rods that they installed, and what happened is that eventually, one of the rods failed.”
Singer says the agency's bridge experts have been dispatched to assist the state Transportation Department in finding out why that fix failed.
Professor Abollhassan Astaneh, who teaches structural engineering at UC Berkeley, suspects that Caltrans was too hasty in trying to make the eyebar repairs last summer, without fully understanding what caused the bars to fracture in the first place.
"When you repair a member, you have to repair it in a way that it still has the same strength, and your repair doesn't fail," said Astaneh.
He says the eyebars are critical to the structure of the cantilever section of the bridge. If one fractures and fails, the other eyebars could as well, and the entire bridge could collapse.
He also thinks Caltrans should close the bridge to heavy trucks until engineers can ensure that the span is structurally safe.
(MGO/kmi)
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