Inspectors have discovered a 10-inch crack in a wishbone-shaped steel beam in the San Mateo-Hayward Bridge.
Despite the crack, Caltrans expected the bridge would remain open, with just the bridge’s northernmost lane – the lane immediately over the crack – closed as of Wednesday night. That lane was expected to stay closed until at least Thursday afternoon.
The beam is located on the flat, water-duct section of the bridge, just before the westbound incline. It was installed in 2001 as part of a seismic retrofit of the bridge, said Caltrans spokesman Bob Haus.
The cracked beam is under the slowest – or rightmost – of the westbound lanes, which typically carries the heaviest truck traffic, said California Highway Patrol officer Peter Van Eckhardt.
The problem was discovered during a scheduled inspection of the bridge on Wednesday afternoon, said Haus. He said it wasn’t clear yet why it may have cracked, but said it was one of many beams of that size and shape under the bridge.
Caltrans staff was expected to work through Wednesday night and into Thursday afternoon to bolt two steel plates onto the beam, in an effort to keep it from cracking further. Once those plates are secured, all lanes of the bridge should be safe to drive on again, Haus said.
Last year, Caltrans inspectors found a large crack on a beam holding up the Bay Bridge. The bridge closed for the temporary repair, but then that repair collapsed about 6 weeks later, causing the bridge to close for several more days.