Bay Bridge officials conceded Wednesday that a lack of quality control led to the installation of at least 30 steel rods in the new eastern span that are now damaged and need to be repaired.
In total, 288 threaded steel rods were encased in concrete atop two towers rising out of the water. The roadway section of the new self-anchored suspension span is bolted to the rods to help stabilize the structure in the event of an earthquake.
Of the 100 rods surveyed by Caltrans this month, nearly one-third have been found to be deficient.
“Given the significant number of the failure of the bolts, I think there clearly was a quality-control failure,” said Steve Heminger, executive director of the Metropolitan Transportation Commission, the regional agency that manages the Caltrans-owned bridge.
While investigators are still reviewing the problem, it’s likely that the presence of hydrogen in the rods caused the damage, said Caltrans bridge manager Tony Anziano. The phenomenon, called “hydrogen embrittlement,” is not unheard of and can be tested for during quality-control procedures, Anziano said. Several members of the MTC’s governing body questioned Anziano on Wednesday about why the steel wasn’t more closely tested if hydrogen issues aren’t an uncommon and undetectable problem.
While Caltrans officials rigorously tested some of the steel rods, not all of the pieces were tested for quality because that isn’t the industry practice, Anziano said. Caltrans conducted the tests alongside representatives from Dyson, the Ohio-based manufacturer that provided the rods. Calls to Dyson were not returned Wednesday.
Because the rods are buried deep in the concrete, many of them cannot be removed. Engineers likely will have to develop an alternative system for stabilizing the span. Caltrans possibly will need to construct an exterior harness that would have the same stabilizing effect, Anziano said. The cost of such a project is not yet known, but it could be billed to the manufacturer that provided the steel, according to Heminger.
Any process could take months and jeopardize the Labor Day opening of the new span, Anziano said.
While he said he’s confident that the bridge will open on time, he added that it would not be cleared until it’s deemed seismically safe.
The damaged rods are just the latest in a string of problems related to the $6 billion rebuild of the Bay Bridge. Last year, reports swirled that concrete pilings were not hardened before engineers tested them. Numerous other setbacks have significantly increased the price of the project and repeatedly delayed the finish date.