A team of researchers recently shifted its operations to Edmonton, Alberta, from Hong Kong to continue development of a new alignment-control and surveying system for tunnel-boring operations. The city is helping with on-the job testing of the system, which is based on a successfully tested, smaller version for utility tunnels. Researchers aim to have a fully operational system for use in the construction of a large-diameter drainage tunnel this April.“The tunneling industry is losing productivity and having problems with quality control” because it lacks real-time survey data, says Ming Lu, associate professor at the University of Alberta. He says the
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.