A survey of East Delhi has revealed the areas vulnerability to damage from earthquakes,due to unauthorised construction and lack of adherence to norms.
The survey was carried out by the National Institute of Disaster Management with the help of MCD engineers,who were trained for the task.
A representative sample survey of 1 per cent of the total buildings (10,000 structures) was carried out by means of Rapid Visual Screening in all the 64 wards of MCD. The survey covered the entire area of East Delhi,spread over 124 sq kilometres.
The survey revealed some inherent structural defects in the buildings (existing and coming up). It was seen that as one goes higher,open spaces were extended,in both unauthorised and regularised unauthorised colonies. In such buildings,the impact of an earthquake is likely to be severe due to a weak foundation.
As per norms,beams and columns are essential to increase earthquake resistance. Since Delhi falls under Seismic Zone-IV (high damage risk zone) and East Delhi is situated on the Yamuna bed,adherence to norms becomes all the more important.
Also,in many buildings already built or in the process of being constructed,it was noticed that the frame structures (beams and columns) did not cover the entire building in consistent shapes and dimensions.
Multi-storeyed apartment buildings in Patparganj were found to be well-planned for the most part,but most of them were found to have a soft storey on the ground floor,making them vulnerable to damage. Soft storey was also found in some public buildings,like fire stations and hospitals.
Some buildings,particularly in municipal ward 221 (Lalita Park area),were found to have big basements. These were constructed without any expert advice and were in violation of building norms.