Normally, assessing wall thickness in a pressurized water or sewer line and main requires shutting down the line and cutting into it. But broadband electromagnetic scanning is finding increasing use as a viable, non-destructive testing alternative that does not interrupt utility service.This fall, BEM scanning contributed to a condition study of a 1970s-era force sewer main for the Metropolitan Sanitation District of Greater Cincinnati. Malcolm Pirnie, the water division of ARCADIS, Highlands Ranch, Colo., is the assessment contractor.The consultant hired InfraMetrix LLC, Tampa, Fla., to use BEM to scan select locations in the line where analysis and other tests predicted
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.