Quake-proofing U.S. buildings

Published 20 January 2010

An Indian civil engineer has invented a sleeved column braces which help buildings withstand earthquakes; the sturdy brace apparatus surrounds a core of high-performance steel, but is spaced from the sides of the core; the sleeve thus absorbs and dissipates energy, but does not buckle under pressure; several large buildings in California, built in the last few years, have adopted the technology

Whenever U.S.-based steel fabricators Star Seismic or CoreBrace are involved in the construction of a new hospital, school, or a commercial building in the earthquake-prone coast, they pay $60-$80 as royalty to Bangalore’s Benne Narasimhamurthy Sridhara for each brace they supply to make the buildings safe as houses.

Fitted with “sleeved column” braces, the technology for which was developed and patented by the 74-year-old Indian structural steel design consultant, the buildings sway under the onslaught of the most severe earthquakes and storms, but they do not buckle.

The sturdy brace apparatus developed by Sridhara is simple, yet effective. It surrounds a core of high-performance steel, but is spaced from the sides of the core. The sleeve absorbs and dissipates energy, but does not buckle under pressure.

The Economic Times reports that almost a decade ago, while experimenting with several designs that could withstand seismic pressures, Sridhara took a thin rod and inserted it inside a transparent plastic pipe. “When I applied load, the plastic tube prevented the brace from buckling,” he recalls.

The 56-floor Los Angeles Convention Center, the Bennet Federal Building in Salt Lake City, Utah, and the 60-storey One Rincon Hill building in San Francisco are among those fitted with the sleeved column braces that emerged as a result of the experiment.

Despite being successfully implemented in the United States, the design is yet to find takers in India even though the Murugappa group supported him and funded the validation of technology spending about Rs 1 crore. “The destruction caused by the 2001 Gujarat earthquake could have been avoided if the buildings, at least those having more than six floors, had these braces,” says Sridhara, a civil engineer who was educated in Mysore and the United States.

Conventional braces, which do not have any sleeved material for absorbing energy, can buckle under even in an earthquake measuring 5 on the Richter scale, he added. The Gujarat earthquake was recorded at 8 on the scale.

Sridhara, whose invention is referred to in the UnitedcStates as Buckling Restrained Braced Frames (BRBF), is today helping U.S. construction firms save at least 30 percent in costs for each brace. Moreover, Star Seismic and CoreBrace are also able to manufacture the braces in the United States instead of importing them from Japan’s Nippon Steel, the world’s second largest steelmaker.

Unlike in India, there are very stringent rules for constructing hospitals and schools in the United States, and that is why this