Unlike many architects, Jeanne Gang, designer of Chicago's mesmerizing Aqua Tower, respects builders and lives for construction. Paul Treacy, the 87-story skyscraper's concrete superintendent, knows this well. Gang had a profound effect on Treacy during construction of her first tower, an innovative residential building that evokes a vertical landscape of rolling hills and ponds. And it is not only because the designer and the “super” bonded over means and methods for Aqua's 78 unique and undulating slab edges, which have extreme cantilevers of up to 12 ft. Gang also left a lasting impression with Treacy on the home front. “My
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.