Soon, all old government and private buildings, and lifeline public structures such as bridges, railways tracks and water supply tanks in the city will need to get a ‘seismic retrofit’ done — they will be modified using cross braces, structural walls, additional beams, columns and other methods to make them more earthquake-resistant.
In a proposal moved by the state disaster management department, an expert committee has been formed to make recommendations on how to make the city more earthquake-resistant. The committee has started the process of auditing public structures and dividing them into different levels. The recommendations will be collated, finalised and incorporated as rules that must be implemented by civic authorities. For private buildings, separate rules will be put in place.
The structures to be modified will include the Mantralaya building that was built around 50 years ago, when the city structures were not built keeping earthquake resistance in mind. Mumbai currently falls in seismic zone III — a moderate damage risk zone.
“Considering the increasing floor space index (FSI) and changes in seismic levels in the last few years, there are certain changes that several buildings and public structures will need to go through. We have formed a committee of disaster management experts and IIT professors who will make recommendations,” said IA Kundan, director of state disaster management department, who has moved the proposal.
Kundan said as the disaster management department cannot directly implement the rules, the government plans to make necessary amends in construction rules, making it necessary for private builders and public authorities to make changes accordingly.
According to leading city architect Hafeez Contractor, who welcomed the move, structures built before 1969 did not follow any building codes that required consideration of the seismic zone an area fell under. “If you consider old buildings in South Mumbai, they were built differently. Now Mumbai has moved two notches up as far as seismic levels are concerned and we need to make changes accordingly,” he said.