EARTHQUAKE RESISTANT DESIGN AND CONSTRUCTION PRACTICES IN INDIA
During the last decade and half, we have witnessed earthquakes of damaging effects in different characteristic earthquake sources i.e. continental collision boundary (Himalaya); subduction zone (Andaman & Nicobar)’ ancient rift (Narmada, Kutch); non rifted zone (peninsular shield) and reservoir triggered (Koyana). Earthquakes of Killari (Latur) 1993, Jabalpur 1998, Chamoli 1999, Bhuj 2001, Andaman- Sumatra 2004 and Muzaffarabad 2005 have revealed that human and property losses are mainly due to collapse of very large vulnerable building stock in the region.
Post Disaster studies, especially after Bhuj earthquake, have given the engineering community - both architects and structural engineers number of important lessons to be adequately addressed so as to mitigate the effect of such hazards in future. Existence of non-engineered buildings, no doubt, has been one of the major cause of collapse of buildings in most of the affected regions but poor quality of construction materials was also observed to be an important cause of failure of RC structures specially in Ahmedabad area, which is about 300km away from the source of the earthquake. Indian Standard Codes for Earthquake Resistant Design & Construction prescribes, besides other things, use of proper quality of building materials in a proper way. It is important to follow the provisions of the codes in a sincere way in construction of buildings for mitigating the effect of such hazards in future. Earthquake resistant buildings are required to have the ability to sway back and forth during an earthquake and to withstand earthquake effects with some damage, but without collapse. For this the structure, particularly their main elements, need to be built with ductility in them. To achieve the required performance it is also important to have right selection of building materials and techniques.
Source : ASDMA