A relatively simple formula can predict how well buildings withstand earthquakes, according to lab work and research in Haiti by Purdue University. The studies suggest how to strengthen existing buildings at a low cost and how to make new buildings damage-resistant. Photo: Courtesy of Purdue University Purdue engineers tested their new seismic index theory by building and then shaking a three-story building in a lab. After the January 2010 earthquake, Purdue professors Santiago Pujol and Ayhan Irfanoglu, both civil engineers, surveyed 170 buildings in Haiti. They concentrated on two- to five-story buildings that were made with reinforced-concrete exteriors. About 40%
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.