While reliable studies of craft labor productivity in the U.S. are in short supply, a few recent reports that specifically address changing trends in construction over the last decade indicate declines in productive output of skilled trades and rising project costs can be traced to gaps in education and training among non-union workers. Photo: Istockphoto HITE Extensive research conducted by noted organizations in the public and private sectors both attest to this trend. These include one groundbreaking study from the private research firm Independent Research Analysis Inc. (IPA) and another key report from the National Institute of Standards and Technology
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.