A top state official said Monday that the Bay Bridge is safe following six days of repairs but admitted that more could have been done to prevent a mishap last Tuesday that damaged three cars and forced the bridge to be closed.
Speaking to reporters about five hours after the span reopened about 9 a.m. Monday morning, Dale Bonner, secretary of the state Business, Transportation and Housing Agency, said, "The Bay Bridge remains safe for the traveling public."
But Bonner conceded, "In hindsight, the tie rods should have been secured" when crews made emergency repairs to a cracked eyebar over Labor Day weekend.
Two tie rods and a crossbar in the section that had been repaired over Labor Day weekend fell onto traffic on the upper deck of the Bay Bridge, just east of the new S-curve, about 5:30 p.m. last Tuesday. The bridge was closed shortly afterward.
Bonner said securing the steel assembly to be safe in high winds and other difficult conditions "should have been part of the original design and it wasn't."
He said, "A very important lesson has been learned."
Bonner said California Department of Transportation officials are confident that the repairs workers have performed will prevent the steel assembly from falling again but even if such an incident re-occurred there are restraining devices, such as tethering straps and cables, to prevent it from falling onto traffic.
In addition to securing the securing the repair system's components in place, Bonner said the updated design has achieved two other important goals: reducing vibration in the tie rods and reducing the potential for metal-on-metal contact.
Joining Bonner at a news conference at a Caltrans office near the Bay Bridge, Caltrans chief engineer Richard Land said metal-on-metal contact was "the most significant" reason the steel assembly section failed and fell.
Land said, "It looks like it was a classic fatigue failure" caused by excessive movement of the tie rods during high winds last week.
Land said Caltrans crews will inspect the repaired section every day for at least the next two weeks and will continue to inspect it regularly afterward.
He also said Caltrans will look at developing "a better solution" for the repaired area for the long term that won't require daily monitoring.
Land said it will take the agency at least four or five months to develop a better solution and implementing a new system might force the Bay Bridge to be closed completely again for a short period.
He said Caltrans officials would plan ahead to try to minimize the length of any such closure.
There are 1,680 eyebars on the Bay Bridge, Land said.
He said Caltrans is checking all of them for cracks and dings and hasn't found any problems.
Bonner said the eyebar crack that was discovered over Labor Day weekend "hasn't gotten any worse" and state officials believe it's safe.
Land said the section that was repaired over the last six days passed a stress test, which consisted of running trucks on the lower deck of the bridge to make sure that the vibration was only minimal.
Bonner said the repair work was observed and approved by several outside experts, included Federal Highway Administration officials and Freider Seible, the dean of the Jacobs School of Engineering at the University of California at San Diego, and Professor Ahmad Itani of the Department of Civil Engineering at the University of Nevada, Reno.
In a statement released by Caltrans, Seible, who's a member of the agency's Toll Bridge Seismic Safety Peer Review Panel, said, "I am satisfied that the work performed by Caltrans over the last five days has returned the Bay Bridge to a safe condition."
Seible said, "Caltrans has also taken other prudent steps, including committing to extensive monitoring and aggressive pursuit of a longer-term solution."
Itani, in a statement issued by Caltrans, said, "Caltrans has approached repairing the damage eyebar system on the Bay Bridge in a diligent and thoughtful manner. I believe that the improvements they have made to the eyebar repair system will insure that the bridge is safe for public use."
