The Unnatural Side Of The Haiti Quake

by Bradford Plumer | January 14, 2010

A massive 7.0 earthquake that erupts beneath a poor, densely populated city is going to have horrifying consequences in any scenario. But as Henry Fountain reports, the devastation in Haiti was made so much worse by the shoddy construction of buildings in Port-au-Prince:

Mr. Sinclair said that design and construction were far worse than in other developing countries he had visited. “In Haiti, most if not all of the buildings have major engineering flaws,” he said.

Most houses and other structures are built of poured concrete or block, there being very little lumber available due to mass deforestation, said Alan Dooley, a Nashville architect who designed a medical clinic, built of reinforced concrete, in Petite Rivière de Nippes, a fishing village 50 miles west of Port-au-Prince.

Concrete is very expensive—much of the cement for it comes from the United States, Mr. Dooley said—so some contractors cut corners by adding more sand to the mix. The result is a structurally weaker material that deteriorates rapidly, he said. Steel reinforcing bar is also expensive, he said, so there is a tendency to use less of it with the concrete.

Building codes are limited or nonexistent, so columns and other elements made from concrete are often relatively thin, designed without proper margins of safety. “We would double the design strength, just to give it a factor of safety,” Mr. Dooley said, referring to practices in the United States. “There they’d design it to what it would hold.”

Another problem was that no one ever expected an earthquake. A lot of the construction was geared toward withstanding the deadly hurricanes that ravage the island every year (see Amy Wilentz's old piece for why Haiti is far more vulnerable than other Caribbean nations during hurricane season—poor governance and mass deforestation again play starring roles):

When builders in Haiti do take disasters into account in their designs, their most recent experience has been with hurricanes, the last major earthquake having occurred two centuries ago. “Newer construction has been developed to withstand hurricanes, not earthquakes,” said John McAslan, a London architect who has studied Haitian buildings, working with the Clinton Global Initiative. “If you engineer for one you’re not necessarily covering the other.”

The Los Angeles Times adds a stunning statistic on the difference that better building codes and construction can make in these disasters: "Before about 1950, a given-sized earthquake would do about the same amount of damage in the developed and underdeveloped world, said Ross Stein, a geophysicist with the U.S. Geological Survey in Menlo Park, Calif. Now the loss of life is typically 10 times higher in developing countries and the damage can be as much as 100 times higher, he said."

(Flickr photo credit: UNDP)

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