Most steel fasteners safe on San Francisco-Oakland Bay Bridge: officials

By Michael Fleeman (Reuters) - The vast majority of steel rods and bolts holding together a new section of the San Francisco-Oakland Bay Bridge are safe, state investigators said Thursday, despite earlier cracks in about 32 fasteners on the span, which replaced a section of the bridge lost in a 1989 earthquake. A draft report to be presented to earthquake safety overseers on Friday shows that the rods and bolts that cracked had been weakened by sitting in puddles of rainwater for up to five years before they were tightened, but the remaining 2,200 connections had not been exposed to those conditions. “The remaining ... high-strength steel rods used on the bridge can safely remain in service with continued inspection and maintenance,” the report said. The report said the fasteners required only “additional corrosion protection” rather than replacement as some critics have called for. The report said the corrosion protection would be “safer for workers, more timely, more cost effective, and, in addition, is consistent with industry experience.” The bridge was damaged in the 1989 Loma Prieta earthquake. Efforts to repair and rebuild it were plagued by years of financial and design problems. Cracks appeared on bolts on support rods shortly before the reopening last year, generating fears about the safety of 2,047-foot-long main span and leading to retrofitting but not replacement of the bolts. The new report said the cracked rods came from different batches than the rest of those used in the project. The rest of the rods are stronger because they had not been soaking in water and because they came from separate manufacturing batches, the report said. “These rods, which were fabricated in 2006, 2010 and 2013, were fabricated differently, and installed differently, than the 2008 rods," the report said. "They also exhibit better material properties.” The report will be presented Friday to the oversight committee, made up of state and local transportation officials. The new eastern section of the Bay Bridge opened in September 2013, six years behind schedule and five times over budget, becoming the world’s largest self-anchored suspension span. Safety concerns have long dogged the project. An independent report this month by retired Bechtel engineer Yun Chung blasted the state’s investigation of the bolts and rods, calling the analysis erroneous, misleading and unscientific. It recommended replacing hundreds of fasteners. (Michael Fleeman reported from Los Angeles; Editing by Sharon Bernstein and David Gregorio)