The Washington Monument in Baltimore has been closed to the public in light of a recent engineering study that found its parapet to be unsafe. CVM Engineering of Philadelphia studied the 178-ft-tall marble monument, which predates the Washington Monument in Washington, D.C., as part of a $200,000 master plan to restore the monument and its surrounding squares. CVM reported that, on the parapet, mortar between slabs was missing and metal support brackets were rust- ed and should be replaced. Engineers recommended $1 million in total repairs, including $300,000 for work on the parapet. The monument, which was completed in 1829,
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.