The deteriorating state of our aging infrastructure has become a pressing concern at all levels of government, but one part we don't hear much about is underground storm piping culverts and sewer systems. The owners of such systems have long recognized that the only way to adequately ensure a product's service life is to confirm that ithas been both designed and installed correctly. Most operators now also recognize that some type of post-installation quality assurance is essential to confirm that the pipe system was not damaged during construction in a way that could result in inadequate structural capacity, excessive maintenance
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.