The top oversight official for construction of the San Francisco-Oakland Bay Bridge rejected independent engineers concerns that key anchor rods were improperly evaluated and remain at risk, but announced a public forum to discuss lingering doubts.
Steve Heminger, chairman of the Toll Bridge Program Oversight Committee, dismissed a critique by local engineers Yun Chung and Lisa K. Thomas as inconsequential. The two engineers noted numerous errors in an official report that cleared the way to the new spans opening in September.
(T)he vast majority of instances you cite involve typographical mistakes, quibbles over punctuation and terminology, and unsupported assertions on your own part that differ from the statements in our report, Heminger wrote in a letter to Chung. I dont believe the public is well served by cataloging such inconsequential matters and attempting to conflate them with issues of real importance to the structural integrity of the new east span.
Chung, a retired Bechtel Corp. metallurgist, and Thomas, a materials engineer at Berkeley Research Company, prepared a 105-page technical evaluation of the oversight groups findings. They later wrote an 18-page supplement after a request for additional details from The Sacramento Bee.
Their unsparing assessment said that hundreds of high-strength rods on the new span were inadequately reviewed and their durability remains in doubt. They said officials understated the effects of corrosion caused by years of exposure to standing water on bolts that snapped in March. Officials also failed to address hardness characteristics in numerous rods that could make them more susceptible to becoming brittle over years of use, Chung and Thomas wrote.
The two engineers warned that without more sophisticated evaluations, the rods might fail over time causing catastrophic damage in a worst case.
Conclusions by Chung and Thomas were endorsed by a peer review panel of eminent engineers. Sen. Mark DeSaulnier, D-Concord, chairman of the Transportation and Housing Committee, said the two engineers work increases the urgency to complete pending independent reviews of the new span.
Heminger noted that the oversight groups report mentioned the possibility that water might have played a role in the broken rod problem, claiming that Chung and Thomas are manufacturing a disagreement where there is none.
Still, he promised to convene a public forum soon to to provide an opportunity for a technical exchange between our engineering and metallurgical team and you, your peers and any other interested parties.
While calling the critics doubts misplaced, Heminger said that officials are committed to taking all prudent precautions to ensure the steel fasteners on the new bridge perform their intended function throughout the design life of the structure.
Hemingers deputy, Andrew B. Fremier, separately emailed his appreciation to Chung for his technical insights. Chung, Fremier and a consultant for oversight officials will meet to discuss technical issues Jan. 7.
Call The Bees Charles Piller, (916) 321-1113. Follow him on Twitter @cpiller.