California Department of Transportation spokesman Bart Ney said this afternoon that the Bay Bridge will likely remain closed during the Thursday morning commute because “there’s still a sizable amount of work to be done” before it can be reopened.
Ney continued to urge people to make alternate commute plans and Bay Area transit agencies have modified service in attempt to accommodate the increase in riders.
The emergency repairs come after a steel crossbeam and two steel tie rods fell off the bridge’s eastern span onto the upper deck near the new S-curve at about 5:30 p.m. Tuesday evening. Three vehicles were struck and an occupant of a Ryder truck suffered a minor injury due to shattered glass from the fallen debris.
The crossbeam and rods were used in temporary repair work done to fix a cracked eyebar spotted on the bridge over the Labor Day weekend.
Ney said there were four tie rods, two on each side, that held the 3-foot-wide steel crossbeam in place. Caltrans is replacing all four tie rods, not just the two that fell off, according to Ney.
It appears that high winds caused the crossbeam and rods to fall.
“It looks like wind was a contributing factor to fatigue on the tie rods,” which caused vibration that made them collapse, Ney said.
More high winds today were delaying efforts to fix the problem because Caltrans wants to make sure that workers are safe, he said. Winds appeared to be dying down this evening, but still have the potential to impact work.
Workers are handling thousands of pounds of steel 120 feet above the deck of the bridge and 200 feet above the water, Ney said.
Ney said once the steel is in place and the welding is completed it will take at least three hours to test the tension in the rods. Then there will be additional testing to make sure the bridge is safe enough to be reopened, he said.
Asked if the bridge will be safe when it reopens, Ney said, “We have some of the best design engineers working on the bridge. It should be safe when we reopen it.”
Ney said Caltrans invited the Federal Highway Administration to look at Caltrans’ designs and enhancements to that section of the bridge. There will be some new enhancements to address the issue of fatigue caused by the vibration.
Abolhassan Astaneh-Asl, a civil engineering professor at the University of California at Berkeley, said today he finds the failure extremely troubling.
In his 40 years of experience as a structural engineer, including 20 years studying the Bay Bridge since the Loma Prieta earthquake, Astaneh-Asl said he had never seen a repair fail.
Astaneh-Asl said that what is most worrisome is that the failure occurred less than two months after the Labor Day weekend repairs, and under such little stress, given that Tuesday’s winds were only moderate.
He said the cracked eyebar is one of 64 identical pieces on the bridge, and that crews should inspect each one, not just by sight but with ultrasonic and X-ray equipment to see if they also have experienced deterioration.
Astaneh-Asl said he hopes Gov. Arnold Schwarzenegger will step in to prevent a second equipment failure on the bridge.
“Don’t allow them to put the same failed repair back on the bridge,” he said. “Even with minor changes, that repair is wrong.”
“If you don’t believe me, just look at the news announcements yesterday: it failed,” he said. “We were lucky yesterday no one got hurt or killed, but next time you can’t guarantee that luck.”