Following a recent Sacramento Bee investigation, Caltrans fired two employees implicated in an assortment of problems involving tests conducted on the Bay Bridge and other structures throughout California.
The Bee reported that Duane Wiles, a technician who was responsible for testing bridge foundations and his supervisor, Brian Liebitch, were involved in at least three confirmed falsifications. The report also revealed several errors committed by Wiles that have called the validity of his testing methods into question, raising concern about several California structures.
The Sacramento Bee’s report relied heavily on the opinion of two internationally known experts in bridge foundation engineering and testing. Bernaard Hertlein of Aecom Technology Corp., a leading Los Angeles construction consultancy firm, and Dan Brown of Tenessee-based firm Dan Brown and Associates reviewed hundreds of documents relating to the Bay Bridge’s self-anchored suspension span that is currently under construction. Brown and Hertlein are considered to be two of the foremost construction experts in the nondestructive testing of deep-foundations, the field relevant to the Bee’s exposé.
In addition to relying on construction experts, the Bee interviewed state Department of Transportation officials, engineering experts and reviewed 50,000 internal Caltrans reports. The Bee reached out to a variety of construction experts when conducting the investigation, though many of the experts declined to comment due to conflicts of interest regarding their professional relationship to Caltrans, one of the nation’s biggest public administrators.
Caltrans insists that the structures are all safe, including the main tower of the new Bay Bridge set to open in 2013—the new Bay Bridge is reported by Caltrans to be able to withstand even the strongest earthquakes. However, when Wiles and other test technicians are found to be discarding raw data files, it makes one question the integrity of the structures, not to mention the integrity of Caltrans inspectors.
Bernard Hertlein, who also co-authored a text on foundation testing, stated that the adequacy of Caltrans tests raises significant questions. He is also concerned that any defects under the main tower would no longer be detectable, “fixing the foundation in any significant way is pretty much impossible,” Hertlein told the Sacramento Bee. “Trying to beef up those existing foundations, which are already so massive, is probably not economically viable under any realistic circumstances.”
Many Bay Area natives remember the terrifying 1989 Loma Prieta earthquake, which caused part of the Bay Bridge to collapse. In the wake of such a tragedy, questions of the bridge’s structural integrity can easily cause public anxiety. According to Hertlein, “the only way to reassure the public is to do a complete review, with top-notch bridge designers … and try to make an educated guess about how the structure would perform in a worst-case scenario.”