Like the London Bridge of the nursery rhyme, the Willamette Bridge is coming down. Under its $140-million general contract, Hamilton Construction Co., Springfield, Ore., orchestrated a complex and eco-friendly demolition for the Oregon Dept. of Transportation’s fair lady. The 2,000-ft-long box-girder bridge, built in 1962, was a key Interstate 5 link between Eugene and Springfield until shear cracks were found in 2002. Truck traffic had to be diverted by 200 miles until a temporary structure could be built in 2004. Eugene-based subcontractor Staton Cos. earlier this year completed demolition of the old bridge, starting with construction of a 120-ft-wide wood-and-steel
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.