2001 Gujarat earthquake: Structural design now at the ‘epicentre’
A decade after the earthquake, the standard of buildings in Ahmedabad have undergone a massive change.
Life has moved on — as it always does — since the devastating earthquake of 2001 but the cataclysmic event left behind many questions about our preparedness in dealing with such disasters.
DNA examines the lessons learnt by government authorities, builders and disaster management agencies, not to say scientists, in the last 10 years, and explores how lives and perspectives have changed since the quake. Instead of merely celebrating the resurgence of the state, we present an insight into where we stand as a society in handling a disaster of this magnitude.
A decade after the earthquake, the standard of buildings in Ahmedabad have undergone a massive change. The natural calamity came as an eye-opener to developers and designers who had ignored the government's guidelines to use better quality concrete and steel, claim structural engineers.
"Structural engineering was once an ignored domain," said former professor of LD Engineering, structural engineer and consultant, VS Shah. "A decade back, structural engineering meant added expenditure and so it was ignored. But after the earthquake, builders and developers have realised that it is the most important part of it. So every building today in Ahmedabad is approved by a structural engineer," he said.
According to Shah, the government had already framed guidelines for using raw materials in construction ten years ago. "Inferior quality of raw material was not the reason why buildings collapsed during the earthquake. Inappropriate designing such as less amount of steel or smaller height of base or incorrect positioning of water tank, were the major reasons that led to collapse of buildings due to earthquake in 2001," he said.
He further added that now, along with good structural engineering and designing, better quality of steel and concrete are being used.
In ten years, developers have made three major changes in construction of buildings, claims city-based developer Vijay Shah.
"First, we have started using ductile steel, which is very flexible. After construction, it can bend but it will not break easily. Second, the quality of the concrete mixture used today is far more superior than what was used ten years ago," said Vijay Shah. "And last, we have started using more steel in footing or base of the building. We have also started using more quantity steel in making columns and beams of the building," he added.
Shah also revealed that now, all the developers strictly adhere to government norms and are making buildings which can withstand tremors worse than the 2001 one. But he also reminded that earthquakes are natural disasters and that builders should not be held responsible for the damage caused. "We are making earthquake resistant and not earthquake-proof buildings," said Vijay Shah.
According to Jignesh Goyani, city-based structural engineer, standard of steel and concrete has been upgraded in ten years.
A decade ago, developers used normal steel and concrete of IS 15 grade, said Ashit Patel, a city-based engineer. "Now, builders have upgraded to TMT steel and IS 20 grade concrete, which is superior," he said.
Meanwhile, some developers have a different story to say. President of Gihed, Suresh Patel said that in 2001, the maximum casualties happened in Maninagar and Paldi areas of Ahmedabad. "It was not because of carelessness of builders but because of these areas are prone to earthquakes. But in the past decade, customers have realised that buildings are being constructed with proper engineering and care. Every developer is constructing earthquake resistant buildings, so the fear of high rises has vanished," said Patel.
In fact now, high rises are the safest, claim Jaxay Shah, director, Savvy Infrastructure and president of Credai, Gujarat chapter. "Even a decade back, low rises or those buildings up to five storeys had collapsed the most in the quake. While low rise buildings collapsed due to their soft floor, high rises collapseddue to inappropriate structural designing. Now, builders are making safer high rise buildings," he said.
Shah said that Ahmedabad falls in zone 3. "It means that many areas of Ahmedabad are prone to earthquakes and so developers have to follow government norms and construct earthquake resistant buildings. But in 2001, developers were not aware that Ahmedabad falls in zone 3."