Before barging and lifting two halves of a 2,650-ton truss assembly for the superstructure of the $1.2 billion Huey P. Long Bridge widening, the contractor wanted to have a way to monitor how the steel was reacting to all of the jostling. MTI, a joint venture of Massman Construction Co., Kansas City, Mo., Traylor Bros. Inc., Evansville, Ind. and IHI Inc., New York, NY, hired Applied Geomechanics Inc. San Francisco to develop a monitoring system that would keep the contractor apprised of stresses to the truss in real time. “As they lift, think of two parallel pieces of paper,” says
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.