Officials in Marion County, Ore., announced they are forming a task force to meet in January that will advise them on a course of action in the wake of myriad structural and construction flaws on the $34-million, 163,000-sq-ft Salem Courthouse Square and its adjacent bus mall. Officials have deemed the five-story, concrete-framed building unsafe, forcing the relocation earlier this year of 300 occupants. A preliminary report by David Evans and Associates says columns inside the structure are not large enough to handle the loads, and that slabs, which contain inadequate post-tensioning, are not thick enough. The report also claims faulty
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.