IIT Delhi develops low cost braces to enhance earthquake resistance in constructed structures

Researchers at the Indian Institute of Technology (IIT), Delhi have developed low-cost, super-elastic, buckling-restrained braces to enhance the earthquake resistance in constructed structures.

According to officials, the braces, for which a patent has also been applied have several advantages, such as all-steel components, on-site fabrication and assembling process, post-earthquake inspection, and easy replacement.

The earthquake resistance of civil structures is often improved by using seismic force-resisting systems or vibration control devices. Buckling-restrained braces are the special structural elements that serve both purposes, they said.

A Buckling-Restrained Brace (BRB) is a structural brace in a building, designed to allow the building to withstand cyclical lateral loadings, typically earthquake-induced loading.

“The proposed technology is effective in the new constructions and has a great potential for the upgradation and retrofitting of seismically deficient Reinforced Concrete (RC) and steel framed structures, such as residential and office buildings, hospitals, and school buildings.We have filed a patent for this technology,” said Dipti Ranjan Sahoo, Professor at IIT Delhi’s Civil Engineering Department.

“These braces can also be conveniently adopted in the steel and concrete bridges to enhance their earthquake resistance. The implementation of this technique in the existing structures reduces overall retrofitting cost and minimises the intervention and downtime. It is possible to design a structure to achieve the required performance objectives in terms of strength and serviceability utilising the hybrid buckling-restrained braces,” he added.

Sahoo explained that the researchers have fabricated novel hybrid buckling-restrained braces (HBRBs) having higher strength, excellent ductility, and better energy dissipation potential.

“The researchers fabricated the braces and studied the seismic performance of more than ten full-scale HBRBs at the full-scale testing facility of the Heavy Structures Laboratory at IIT Delhi. Tests are being conducted on specimens with improvements and modifications at the laboratory,” he added.