An unexpected crack found in a section of the Oakland-San Francisco Bay Bridge delayed the planned Sept. 8 reopening only by about 90 minutes, rather than a full day, thanks to fast delivery from a fabricator and non-stop work by the contractor. Although the $140-million removal of a 3,200-ton double-deck section went as planned, California Dept. of Transportation inspection crews then reported a crack in an eyebar—a 2-in.-thick, chainlike steel piece—located on another section of the east span. Photo: AP / Wideworld Despite unwelcome discovery, bridge detour opened on Sept. 8 as planned. Over the Labor Day weekend, general contractor
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.