Concerns Over Brittle Bay Bridge Steel Rods

Despite intense public scrutiny over its brittle bolt and rod problem, transportation officials said Wednesday they would cave not cave to any pressure when it comes to safety on the Bay Bridge.

"We will open the new eastern span of the Bay Bridge only when it's ready and not a day sooner," Metropolitan Transportation Commission Executive Director Steve Heminger said at a public meeting. The MTC also serves as the Bay Area Toll Authority, which held Wednesday's meeting.

At the meeting, the Toll Bridge Program Oversight Committee said that hydrogen embrittlement likely cause the bolt failure on the bridge, and they are looking at two possible fixes: Putting steel collars over the bolts that could hold seismic devices or putting a steel saddle over them.

The committee did not pick an option, but is expected to do so on May 8. At that point, officials said they may be ready to state whether the bridge will be ready by Labor Day, which has long been the plan.
 
Thirty-two of  the bridge rods failed while being tightened in March. The rods connect steel earthquake safety devices called shear keys to the deck of the bridge and a large concrete cap.

``Even though 32 of the 96 bolts have failed, we are writing them all off.  We are not counting on any of them,''  California Department of Transportation Director Malcolm Dougherty said.
 
Officials have said they could take months to replace.
 
The $6.3-billion bridge, which is replacing a span damaged during the 1989 Loma Prieta earthquake, is designed to withstand a major temblor. It is already years late in opening and billions of dollars over budget.
 
The best explanation investigators have found so far for the broken rods is that somehow they were permeated by hydrogen, making them brittle. 
 
Another batch of 192 bolts from 2010 has been installed, and though state transportation officials have reported no failures in those bolts, Heminger said officials are still considering replacing them.
 
He said he could not yet estimate how much that would cost, but Dougherty said after the meeting any fix will exceed $1 million, and taxpayers ultimately may be hit with some of that cost.
 
The new bridge, which is replacing a span damaged during the 1989 Loma Prieta earthquake, is designed to withstand a major temblor. It is already years late in opening and billions of dollars over budget.
 
Documents released this month by the California Department of Transportation show its inspectors found structural integrity issues with some of the bolts several years ago, before they were installed.
 
The documents were unclear about whether the problems were remedied before the bolts were delivered and installed. The inspectors noted that the bolts failed elongation tests for structural integrity and said they were concerned about the quality of work by a company that galvanized the bolts to prevent corrosion.

 Garance Burke from the Associated Press contributed to this report.

Copyright AP - Associated Press
Contact Us