More than seventeen years after the so-called Great Chicago Flood—a 1992 construction snafu in which a misplaced piling that was driven into the Chicago River hit an abandoned freight tunnel, flooding downtown basements and knocking out utilities—those infamous tunnels are at it again. Slide Show Photo: IDOT On the morning of Oct. 14, construction workers on Chicago’s Kennedy Expressway noticed that pavement was buckling. Directly underneath, workers were grouting an abandoned freight tunnel. On Oct. 14, workers for Lorig Construction, a Des Plaines, Ill.-based roadbuilder, were preparing to finish grouting a section of old tunnels underneath the Kennedy Expressway, 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.