SAN FRANCISCO — Crews will install a temporary fix for broken seismic safety bolts on the San Francisco-Oakland Bay Bridge while long-term repairs are being conducted, but officials are still not sure if the work will allow the span to open Labor Day weekend, a spokesman said Friday.
The California Department of Transportation ordered steel plates that in August will be wedged into moveable bearings that connect to the roadway, agency spokesman Andrew Gordon said.
These wedged-in plates, or "shims," would keep the roadway bearings from moving in the event an earthquake strikes while crews are working on the permanent repair for the faulty 17-foot seismic safety bolts.
Those bolts hold in place a seismic shock absorber called a "shear key" located near the bearings and which help control the bearing's movement during a strong temblor.
"In the event of an earthquake before the permanent repair is made, (the steel plates) are a temporary insurance policy on the bearings while the permanent insurance policy is being built," Gordon said.
The permanent fix, a steel saddle held in place by cables that will replace the clinching function of the failed bolts, is expected to be finished by Dec. 10.
Members of the Toll Bridge Program Oversight Committee, which oversees construction of the bridge, said earlier this month that it is possible the bridge could open to traffic as scheduled if outside analysts approve the shim design.
Gordon said the Federal Highway Administration and a panel of seismic experts would weigh in on the work in mid-August.