Developing Earthquake-Proof Buildings

Destructive earthquakes in Haiti and Chile recently highlight the importance of engineering and testing earthquake-proof systems.

The 8.8-magnitude earthquake that struck Chile last week was much more powerful than the 7.0-magnitude earthquake that struck Haiti in mid-January. Yet it caused only a fraction of the casualties (fast approaching 800) compared with the 300,000 people estimated to have died in Haiti. Some seismologists suggest that one reason for the difference in the death tolls is that buildings in Haiti were constructed quickly and cheaply, while Chile enforced building codes for earthquake-resistant structures after a 9.0-magnitude earthquake in 1960.

"Since the turn of the century, earthquakes have directly or indirectly (including tsunami) claimed the lives of more than 640,000 people, four times more than in the preceding two decades, and proportionately more than the global increase in population would anticipate," according to a recent paper in the journal Nature.

"If buildings are not made earthquake resistant, the toll is likely to continue to rise as cities grow in population," Roger Bilham, a professor of geological sciences at the University of Colorado and one of the first seismologists to visit Haiti after the recent earthquake there, writes.

Earthquakes generate forces that a building's structure may not be designed to endure. During a quake, the ground moves while the building resists the shaking. "Although most of the ground movement usually is horizontal, a quake can also rock a building up and down, like a rodeo rider on an angry bull," TLC's Tremor Tech says.

Hinging on the idea that building to withstand natural forces is not a losing battle, plenty of engineers and architects believe it is possible to design and construct an earthquake-proof building. At study centers throughout the country, many experts are working to develop new technologies that could minimize the dire costs of a major quake.

"Technology designed to keep buildings from collapsing works essentially in two ways," a CNN Tech report this week explains: "By making buildings stronger, or by making them more flexible, so they sway and slide above the shaking ground rather than crumbling."

These videos introduce a range of earthquake labs where engineers and scientists model earthquakes and the architectural damage such natural disasters can cause, while highlighting sites for testing systems and technologies to make manmade structures more earthquake-resistant, perhaps even earthquake-proof.