Caltrans: Bridge is safer this time
By: Tamara Barak Aparton
Examiner Staff Writer
November 2, 2009
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| As crews prepared to open the Bay Bridge Monday, Caltrans assured motorists that the structure’s current fix is safer than its last. (AP ) |
SAN FRANCISCO — As crews prepared to open the Bay Bridge Monday, Caltrans assured motorists that the structure’s current fix is safer than its last.
On Tuesday, several steel repair parts fell onto bridge during peak traffic time, as strong winds cause vibrations that shake pieces loose. The parts had been put into place to fix a dangerous crack discovered Labor Day weekend in a load-bearing eyebar.
Caltrans blamed Tuesday’s break on wind, saying the vibrations wore the metal parts until they broke. On Monday, Caltrans spokesman Bart Ney assured motorists the problem had been eliminated.
“We’ve put in several enhancements to make sure the vibrations don’t cause fatigue again,” he said.
Caltrans has also made adjustments to ensure that if the eyebar fractures again, metal will not rain down on drivers.
Crews placed stronger structural welds on the crossbar that came loose Tuesday, and wrapped the system in a cable.
“If something were to fail up there, it would be held in place,” Ney said. “This is a safer fix related to failure caused by possible fatigue.”
On Sunday evening, Caltrans officials had hinted that they would “look into other possibilities” to repair the bridge if the fix continued to fail stress tests. But on Monday, Ney said crews were able to make the repairs without changing course on the design.
“We are still confident this was the best design to fix the crack in the eyebar,” he said.
Monday morning, large trucks were lined up to rumble across the lower deck of the Bay Bridge, so engineers could test how the upper deck handled the vibrations. Visual inspections of the fix were underway, and crews were completing final supports in the damping system that will control vibrations during an earthquake.
Unless problems are discovered during the final inspections, the bridge could open as early as late Monday morning.
“We’re further then we’ve ever been before,” Ney said.
Meanwhile, BART continues to run longer trains after commuters shattered historic ridership records last week.
Caltrans will continue to monitor the repairs to the bridge. Daily lane closures during non-peak hours are likely, Ney said.
