During a routine inspection, Caltrans engineers identified a crack in a wishbone-shaped steel beam located beneath the affected lane and immediately closed the lane.
The affected beam was originally installed as part of a seismic retrofit completed in 2001 that allows for the bridge to move back and forth during an earthquake, according to Caltrans.
Engineers quickly set to work on a repair design, which called for several high-strength steel plates to be bolted in place over the cracked section.
Over the weekend, Caltrans engineers regularly reviewed progress and designed additional repairs to maximize the beam’s strength–four plates were originally called for, but officials decided Friday to add at least one more.
Although the redesign required more time, Caltrans said the benefit of long-term safety for drivers outweighed the short-term inconvenience of the lane closure.
Crews worked to complete repairs ahead of a football showdown scheduled for 1:05 p.m. today at Candlestick Park in San Francisco pitting the San Francisco 49ers against the Oakland Raiders.
The lane was reopened at 3:19 a.m.
Caltrans said engineers will continue to monitor the repaired beam section, and additional off-peak lane closure may be required to ensure safe use of the lane.
Patricia Decker, Bay City News