New Technique enhances Ductility of Vulnerable Buildings

Brief

Researchers at the Indian Institute of Technology Kanpur have found that a semiconfined unreinforced brick masonry technique to retrofit seismically vulnerable buildings resulted in increased ductility and energy dissipation. It not compromise their strength of the retrofitted buildings.

Insight

Researchers have found a solution for retrofitting old non-earthquake-resistant buildings with a technology that can prevent major damage to such buildings from earthquakes without compromising on their strength.

The technology called semi-confined unreinforced brick masonry (SC-URBM) can resolve the problem of spread of settlements in earthquake-prone areas with constructions that have been built without following earthquake-preventive building codes.

Historically, most buildings, technically called unreinforced masonry (URM), were not built using modern building codes. Thus they are much more likely to experience damage or collapse during an earthquake. URM buildings have traditionally been widely adopted worldwide due to inexpensive and locally available construction materials.

Just like in most developing countries located in earthquake-prone regions unreinforced brick masonry (URBM) has been a common practice in urban, semi-urban, and rural areas of India. Considering that major parts of India are under seismic zone III or above and most of the URBM buildings are old and structurally deficient, strengthening of URBM buildings located in earthquake-prone areas is extremely important.

Researchers from Indian Institute of Technology, Kanpur, have explored the extent to which retrofitting old buildings with SC-URBM technology can solve the problem. They found that SC-URBM can significantly enhance the energy dissipation capacity and ductility of the retrofitted building without compromising its strength. Hence such buildings would have resulting superior performance in comparison to URBM buildings during earthquakes.

The idea of the technology emerged from confined masonry, an earthquake-resistant construction system where the masonry walls are built first, and the concrete columns and beams are poured in afterward to enclose (confine) the wall. SC-URBM technology has a similar concept but does not need to be implemented at the construction stage.