Foreclosures, unemployment, tighter lending and unstable prices weigh heavily on the commercial housing sector, but falling demand has not had a similar effect on the cost of materials. Photo: Pulte Corp. Production cuts at U.S. and Canada mills propelled a 40% price increase since 2009. Related Links: Economics: Despite Upturn in Steel, Lumber and Energy Prices Deflation Sweeps Cost Index Board Markets: Survey Shows Contractor Confidence Slowly Rising Glass: Recession Shatters Prices, More Cuts Expected During 2010 Executive Pay: Key Players Dodge Salary and Bonus Squeeze Methodolgy: What is Driving Costs ENR's Complete First Quarterly Cost Report 2010 City Indexes:
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.