SAN FRANCISCO (KCBS)—As Caltrans officials scramble to figure out just what went wrong with the seismic safety anchor rods on the Bay Bridge’s new eastern span and how to repair them, they are paying close attention to an unsolicited report from a retired engineer.
MTC and California Department of Transportation officials learned recently that about one-third of the 96 bolts that were installed on a pier just east of Yerba Buena Island had popped out several inches after they were tightened.
Those bolts, which were manufactured in Ohio in 2008, are located near where the new span’s self-anchored suspension span meets its skyway.
Metallurgist Yun Chung, a retired engineer who once worked for Bechtel , produced a 32-page report that cites inadequate steel specifications and claims Caltrans engineers were ignorant to the threat of hydrogen embrittlement—a process in which high strength metals, such as steel, become brittle and fracture due to hydrogen exposure.
Retired engineering professor Charles McMahon at the University of Pennsylvania has read Chung’s report and agrees with his findings.Comments (3)