The Occupational Safety and Health Administration’s regulatory agenda for the first half of 2010 contains some major construction rules, including a long-awaited final regulation on cranes and derricks and a proposed rule on crystalline-silica exposure. Both regulations are expected to be issued by July. Construction industry groups and labor unions say they expect OSHA to be more active on the regulatory front under Labor Secretary Hilda Solis and new OSHA chief David Michaels, confirmed to the post on Dec. 3. But industry organizations say they find the agency’s shift toward enforcement from cooperative alliances troubling, although not unexpected in a
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.