China plans to award a design-build contract soon for the sunken tube tunnel and artificial islands comprising part of the 30-kilometer-long, $5.5-billion road link between Hong Kong, Zhuhai and Macau, in the Pearl River Delta. Bids for the bridge section will follow in a few months, says a project source. Officials plan to open the link in 2016. Road link across the Pearl River Delta will include a sunken tube tunnel and artificial islands. From Hong Kong, some 5 km of bridges will link to two 700-meter-long islands, which will be linked by the tunnel. The crossing will continue on
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.