Photo Courtesy of Caldecott/ Tutor Perini Tutor Perini bores a $214.8-million two-lane Caldecott tunnel. The weak economy has squeezed transportation budgets to the limit. Still, firms that work in the transportation market are finding ways to push forward, diversifying their businesses by sector and region and looking to alternative delivery methods, such as public-private partnerships.Richard Cavallaro, president of Skanska USA Civil, Whitestone, N.Y., says it is hard to plan ahead not knowing when a federal transportation bill will be enacted and with states being financially strapped. While the American Recovery and Reinvestment Act has helped sustain active projects, he says
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.