NDMA says residential high-rise towers don't conform to earthquake safety standards; comes up with norms on seismic retrofitting

NEW DELHI: Do you live in one of those fancy residential high-rise towers that solved the urban parking crisis by having an open ground storey car parking? If yes, the government has just ruled that your flat may not be safe from an earthquake.

The National Disaster Management Authority (NDMA) under the home ministry has come out with norms on seismic retrofitting of deficient buildings and structures and called for a "National Retrofit Programme" to ensure critical government buildings and select private buildings like schools, hospitals and banks are retrofitted urgently.

NDMA, which prepared these guidelines along with top experts from IITs, state governments and ministries, has raised the red-flag on one of the most visible residential structures coming up in the country’s cities — open ground storey reinforced concrete (RC) buildings, that do not have a flat on the ground floor but an open car parking.

"A special class of buildings has emerged in a big way across the country, called open ground storey buildings (or buildings on stilts). This is a solution being provided by architects to solve the parking crisis in urban India, but it does not address earthquake safety of these buildings. These do not conform to prevalent Indian standards for earthquake safety. These buildings are flexible and weak in the open ground storey compared to the storeys above," the norms say.

NDMA has stressed that a large number of such low-strength RC buildings collapsed during the 2001 earthquake in Bhuj in Gujarat. "Most of these buildings, not designed properly, may be able to carry gravity loads, but could be deficient in strength to withstand deformations imposed on them during strong earthquake shaking," the NDMA guidelines said. NDMA has, however, said that during the 2001 Bhuj earthquake, many such buildings with open ground storey that were owned by the government did not collapse because they had been designed as per the Indian Seismic Code.

NDMA has said across urban India, most multi-storied buildings are being made of RC — a composite material made of cement concrete embedded with small diameter steel reinforcement bars.