Caltrans Completes Bay Bridge Eastern Span 10-Year Structural Assessment ​

Caltrans has released the results of the 10-year comprehensive structural assessment of the Bay Bridge eastern span, and the verdict is: the $6.5 billion self-anchored suspension bridge is performing within design parameters. Somewhere, a Caltrans public affairs officer just exhaled for the first time since 2013.

The assessment included detailed inspection of 4,500 structural elements, load testing, seismic sensor analysis, and — everyone's favorite topic — an update on those pesky high-strength steel rods that were found to be susceptible to hydrogen embrittlement during construction. The rods are "performing satisfactorily under the implemented mitigation measures," which in engineering confidence-speak falls somewhere between "it's fine" and "please don't ask follow-up questions."

Rod Situation Update ​

For those who have mercifully forgotten the rod saga: during construction, 32 of 424 high-strength anchor rods cracked due to hydrogen embrittlement, a metallurgical condition where steel becomes brittle in the presence of hydrogen. The fix involved dehumidification systems in the affected anchor housings and long-term monitoring. Ten years later, the dehumidifiers are working and no additional rods have cracked, which is the engineering equivalent of "the patient is stable but we're keeping them overnight for observation" — permanently.

Overall Condition ​

The assessment rates the bridge's overall structural condition as "good," with particular praise for the orthotropic steel deck performance and cable anchorage integrity. Minor issues include some corrosion in the steel shell pile connections (predictable for a structure sitting in saltwater) and wear on several bearing assemblies that will need replacement within the next 5-7 years.

Fatigue monitoring shows the deck has experienced approximately 8% of its design fatigue life in 10 years, which is slightly better than projected and means the bridge should comfortably outlive everyone currently reading this article. Small comfort as you're sitting in traffic on it, but comfort nonetheless.