Fear is mounting in the Capital following a series of tremors that shook Delhi in a span of three hours early on Tuesday morning.
The tremors – four measuring 2.5 to 3.3 on the Richter scale and eight measuring less than 2.5 – have also underlined how unprepared Delhi is despite crores being spent on disaster preparedness.
The National Institute of Disaster Management (NIDM) and MCD engineers had carried out a survey in 2011 following a building collapse in Lalita Park of East Delhi that killed 71 persons.
Despite the survey finding that “a majority of 10,000 buildings in East Delhi are not quake-resistant,” nothing has been done on the report so far, NIDM head of the Geo Hazards Division Chandan Ghosh told The Hindu.
“The survey was like conducting a health camp. We found that retrofitting had to be done on a majority of them. We checked the design component, concrete, workmanship and parking space. Theoretically, societies at I.P. Extension have had retrofitting but in practical terms they fall short of the required standard,” he said.
Prof. Ghosh said if the design was okay, the construction process was found to be faulty. “The architect has drawn the design on the computer but the masons continue to work without the use of technology.”
Pointing out that Delhi has not experienced an earthquake measuring over five on the Richter Scale in the past 50 years, Prof. Ghosh said: “Delhi has only been receiving tremors. An earthquake of less than five magnitude will be described only as a tremor. In Singapore or Tokyo there is 100 per cent guarantee for buildings.”
He said a majority of the buildings in the country have not been designed and monitored as per the guidelines laid down by the Bureau of Indian Standards.
“If we examine all the buildings we will be able to detect one fault or the other in all of them.”
Explaining the reason for East Delhi being a seismic-prone zone, Prof. Ghosh said East Delhi has alluvial soil. “When the earth shakes, loose soil which has water collapses. Inevitably, the buildings will also collapse. In such cases, construction has to be scientific. We have to use ground improvement technology, which in layman’s terms means strengthening the ground. But people are unaware of this technology.”
The NIDM, which falls under the Union Home Ministry and has an annual budget of Rs 7-8 crore, imparts free training to architects, town planners and engineers of government agencies.
Tuesday morning’s tremors and the accompanying ‘roaring noise’ created panic among people, with many rushing out of their homes.
Indian Meteorological Department director of seismology, R.S. Dattatreya, said though the series of tremors were rare, they were not unusual. “Such an event occurred in April 2003 too. The tremors were accompanied by very high sound as if a truck was passing by.”