President Obama’s Labor Day call for a new transportation infrastructure program could move public-works spending closer to the national political debate’s front burner. So far, Obama and White House officials have offered only an outline that doesn’t specify how much they want to spend or precisely how the program would work. Photo: Ap/pablo Martinez Monsivals If the framework were converted to detailed legislative language, it would face a tough path on Capitol Hill this year. For one thing, Obama’s plan quickly drew harsh blasts from congressional Republicans. Moreover, the Hill is on a tight schedule: Only about three weeks remain
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.