Shaken, but not stirred!

While real estate is booming in the country, are we really sensitised about earthquake resistant buildings?

Not many of us know that 59 per cent of the Indian land mass is vulnerable to earthquakes, yet most buildings across the country are not geared to handle earthquakes.

In the last 20 years, there have been eight damaging earthquakes across India and the one that finally prompted the revision of the Indian Seismic Building Code in 2002 was the devastating earthquake in Bhuj, Gujarat, on January 26, 2001.

One of the biggest lacunae in our system though is that the existing National Building Code (NBC) is just recommendatory in nature. "A new earthquake code had been incorporated earlier but still a lot of structures are not compliant," says M Ramachandran, secretary, ministry of urban development.

The big question then is, do all builders comply by these codes, as the government's codes are only recommendatory in nature, not mandatory. And how many of us actually ask about earthquake safety when we go to buy a house?

"By and large most reputed builders comply by the codes. They would not risk it and generally follow the norms, but that may not be true for smaller builders, some of whom might not even have sufficient know-ledge about earthquake safety measures," says Uday Dharmadhikari, president, Construction Project Management, Trammell Crow Meghraj.

Both Rohtas Goel, MD, Omaxe and Pradeep Jain, MD, Parsvnath Developers, confirm that all their buildings are fully compliant, at least upto life safety levels.

"The risk perception is very low in our country. Our understanding of earthquakes risks too is very low," says Rajeev Issar, programme associate, GoI-UNDP, Disaster Risk Management Programme.

"The shallower the earthquake, the higher the destructive potential. India is prone to shallow earthquakes," he adds. Some of our major cities are in seismically active zones. Delhi and the whole of NCR is in Zone 4 while Mumbai, Chennai and Kolkata are in Zone 3.

Sandeep Donald Shah of Taylor Devices, a company dealing in retrofitting devices, informs that there are three categories of earthquake resistant structures. 
 

THERE ARE FOUR SEISMIC ZONES IN INDIA
Zone 2	likely to be hit by earthquake of intensity 6 or below
Zone 3	intensity 7
Zone 4	intensity upto 8
Zone 5	intensity 9 and above

The first is earthquake resistant, fully operational (hospitals and other lifeline buildings which need to be operational at all times should be in this category); then earthquake resistant, immediate occupancy (minimum non-structural damage, but building can still be used after an earthquake). And the last is earthquake resistant life safety (which is what has been recommended in the government codes).

Life safety implies that in case of a major earthquake the total collapse of the building should be prevented. This would help in minimising casualties. After the earthquake, in case the damage to the building is above a threshold level, it can be demolished and rebuilt.

The National Disaster Management Authority is setting up new guidelines to reduce the impact of earthquakes in the short and long-term.

At a workshop on earthquake resistant structures organised by the Omaxe Foundation, Professor A S Arya, national seismic advisor to the government of India, points out that one of the biggest concerns today is that there is not enough trained manpower for earthquake resistant construction in the country.

Even the new flyovers coming up across Delhi and the metro project pillars are only being built upto life safety standards and do not use high-end protection by way of shock transmission units, says Shah.

This means there is a possibility of communication lines getting blocked in case of a disaster. He points out that it would cost only 1-2 per cent extra to make these structures earthquake resistant at the time of construction.

According to Professor Arya, the extra cost of making a building earthquake resistant is only 4-5 per cent and in areas which fall under zone 5 (which is the highest), it could go upto 7-8 per cent of the project cost.

Retrofitting costs, on the other hand, could vary from 5-15 per cent depending on a variety of factors. He cautions, "No hospital in Delhi will be operational in case of an earthquake."

But there is hope. The ministry of home affairs along with USAID is supporting a company called GeoHazards International in partnering with the Delhi government to retrofit five lifeline buildings in Delhi.

This is part of a pilot project. GeoHazards, along with Delhi PWD, is retrofitting the Delhi Secretariat building, the police headquarters, Guru Teg Bahadur Hospital in Shahdara, the divisional commissioners office near ISBT, and Ludlow Castle School, also near ISBT. The hospital will be retrofitted up to immediate occupancy levels while other buildings will be upto life safety standards.

Hari Kumar, national coordinator, GeoHazards International, says that this is the beginning of a process to retrofit lifeline buildings before an earthquake comes, not after it has occurred, as has been done in the past.

GeoHazards is bringing in earthquake engineering experts from California (which has seen many devastating earthquakes in the past) to work with the best in Delhi. A team of PWD engineers have also been trained.

The future should see the ministry of home affairs undertake the National Earthquake Risk Mitigation Project which will include retrofitting of lifeline buildings in all districts across the country falling under seismic zone 4 or 5.

Also, a new retrofitting team will be instituted in PWD to take a look at existing buildings and their seismic safety levels.