Washington: Earthquakes never occur when you need one, so US researchers plan to create an artificial quake in the hope of developing sturdier and safer buildings. A team led by Johns Hopkins structural engineers is shaking up a building themselves in the name of science and safety.
Using massive moving platforms and an array of sensors and cameras, the researchers are trying to find out how well a two-story building made of cold-formed steel can stand up to a lab-generated Southern California quake.
The testing in New York, marks the culmination of a three-year, USD 1 million research project involving scientists from six universities and design consultants from the steel industry. The work is taking place in the only facility in the US that is capable of replicating an earthquake in three directions beneath a building measuring 50 feet long, 20 feet wide and 20 feet tall.
The trials will wrap up in mid-August when the researchers will shake the unoccupied structure with forces comparable to those at the epicentre of the catastrophic 1994 Northridge earthquake in Los Angeles, which claimed dozens of lives and caused billions of dollars in damage, researchers said.
The results are expected to lead to improved building codes that will make future cold-formed steel buildings less expensive to construct than current ones. The new codes could, in certain cases, make lightweight cold-formed steel buildings less costly to construct than those made of materials such as timber, or hot-rolled steel.
In earthquake-prone regions, these code updates should help structural designers and builders reduce the likelihood of a costly and life-threatening building collapse. The research could lead to broader use of building components made of environmentally friendly cold-formed steel, made of 100 per cent recycled steel.
Cold-formed steel pieces, commonly used to frame low and mid-rise buildings, are made by bending sheet metal, roughly one-millimetre-thick, into structural shapes without using heat.
Although the material is popular, some large knowledge gaps exist regarding how well cold-formed steel structures will stand up to extreme conditions - including earthquakes. This has caused engineers to be very conservative in their design methods.
The tests being conducted atop two "shake tables" at the University at Buffalo should help close those information gaps and lead to better constructed buildings, said lead researcher Benjamin Schafer.
"This is the first time a full building of cold-formed steel frame has ever been tested in this way, so even the small things we're learning could have a huge impact," said Schafer, professor and chair of the Department of Civil Engineering.