Through the first four months of 2009 the total value of construction starts reached $117 billion, which was 39% less than the first four months of last year, according to McGraw-Hill Construction. “The pattern of construction starts over the past two months suggests a transition from extended declines to more of an up-and-down pattern, which generally takes place when a bottom gets established,” says Robert Murray, MHC’s chief economist. “This process of establishing a bottom is still in its early stages.” The public-works market is expected to see more strength as the impact of the stimulus bill begins to emerge.
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.