In 2013 thirty-two, 3-inch diameter, threaded, high strength anchor rods fractured when tightened during the latter stages of construction of the San Francisco-Oakland Bay Bridge. Hydrogen embrittlement was identified as the failure mechanism. In December the Toll Bridge Program Oversight Committee (TBPOC) submitted its draft final report to earthquake safety overseers, which includes assurances over the safety of more than 2000 similar rods in situ. An experienced independent materials engineer, however, continues to challenge the TBPOC conclusions, recommending much wider scale replacement.(…)
via Continued controversy over Bay Bridge embrittlement failures.