Caltrans: Bay Bridge bolt problem fixed 

click to enlarge bolts
  • Justin Sullivan/Getty Images
  • A worker drills into concrete on the underside of the newly constructed San Francisco-Oakland Bay Bridge on May 23, 2013 in Oakland, California. Bridge workers began installing large steel saddles over two seismic safety devices on the new East Span of the San Francisco-Oakland Bay Bridge to fix a problem with broken bolts on two shear keys.
Workers have finished a permanent fix for problem bolts on the new eastern span of the Bay Bridge, a Caltrans spokesman said today.

Spokesman Andrew Gordon said the work was completed at about 11 a.m. today and cost about $25 million, which is about twice the amount that transportation officials predicted when the bolt problem was discovered in the spring.

Gordon said the cost was higher than originally expected because, "This was a unique, complex problem that demanded a unique, complex solution."

In March, nearly one-third of the 96 bolts that secure earthquake shock absorbers known as shear keys to the deck of the bridge failed when they were tightened.

The shear keys are designed to prevent swaying during an earthquake, which is a key element in the construction of the $6.4 billion span because the goal is to make it seismically safe since a portion of the existing bridge failed in the 1989 Loma Prieta earthquake.

The problem threatened to delay the plan by transportation officials to open the new eastern span, which is intended to be safer in earthquakes than the old span, over Labor Day weekend.

But transportation officials then learned of and approved a short-term fix which involved inserting large steel plates, known as shims, into each of four bearings, enhancing their ability to safely distribute energy during an earthquake.

The long-term solution to fixing the broken bolts on the eastern span was to cover them with an exterior saddle and cable system that is encased in concrete.

Gordon said the temporary shims were removed today.

Several engineering experts have expressed concern that there could be problems over the long term with other bolts on the new eastern span but Gordon said tests are being conducted to address those concerns and see if those bolts must be replaced at some point.

He said those tests are expected to be completed by next fall.

But Gordon said Caltrans officials believe that the new eastern span is safe.

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