Five contractors have submitted proposals to build the $523-million National Bio- and Agro-Defense Facility in Manhattan, Kan., project sources confirm. Construction of the megalab, to be the center of U.S. infectious disease research, is being managed by the U.S. Dept. of Homeland Security. It will replace an aging facility in New York state. DHS would not disclose details of the ongoing procurement, but according to company executives, those proposing to build the facility include: a joint venture of Gilbane Building Co. and Turner Construction Co.; a JV of Mortenson Construction and McCarthy Holdings Inc.; a JV of Bovis Lend Lease
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.