The Washington State Dept. of Transportation is creating a list of best construction practices for floating bridges, based on results of tests conducted on a pontoon built at one-sixth the typical size. The best practices will be used by the design-build team that won the contract to build new pontoons for the state Route 520 Evergreen Point Floating Bridge. At 2,285 meters, SR 520�s bridge is the longest of its kind in the world. Photo: WSDOT Engineers run curing tests on a scale-model pontoon at a yard near Olympia, Wash., in an attempt to minimize cracks. Photo: WSDOT WSDOT and
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.