A Workshop on Microzonation ©Interline Publishing, Bangalore Methodology for Seismic Vulnerability Assessment of Building Stock in Mega Cities *Shailesh Kr. Agrawal and **Ajay Chourasia Scientist, Central Building Research Institute, Roorkee 247 667, *agrawal_shaileshkr@yahoo.com; **ajayapc@yahoo.com Abstract The damage to built environment during recent earthquake in India has demonstrated the need for seismic risk assessment that is capable of predicting the consequences of earthquakes. The collapse of man-made engineered and non-engineered buildings during an earthquake is the chief contributor to the loss of lives and injuries to the people. Vulnerability Atlas of India states that there are about 11 million seismically vulnerable houses in seismic zone V, while the corresponding figure for seismic zone IV is 50 million. In all, there are about 80 million building units in India, which are vulnerable, and pose unprecedented risk, if earthquake strikes. The greatest challenge, therefore, is not only to rehabilitate these vulnerable houses so as to reduce considerable loss to human life and property but also to evolve an accepted methodology in Indian context to estimate/quantify the seismic vulnerability of the existing built environment, which will be provide a useful information for policy making. The paper proposes an approach to estimate seismic vulnerability of existing buildings of a city in Indian context. The scheme estimates seismic vulnerability of existing building stock quantitatively and qualitatively. The quantitative approach covers demand-capacity computation, while qualitative procedure estimates structural scores based on national & international state-of-the-art procedures viz. Rapid Screening Procedure (RSP). The methodology presented would lead to identify buildings that might pose risk in the event of damaging earthquake and would form an integral part of microzonation studies being taken up for Indian vulnerable cities. Preamble The rapid growth of Indian cities in the recent past, have accelerated pressure on housing industry, especially in high seismic zone i.e. Zone-IV & V [16] . The built environment in these zones have been seismically found vulnerable as most of these construction are without earthquake resistant measures. The Indian cities are dotted with all kinds of buildings and infrastructural facilities comprising of very good construction to poorly designed & constructed ones. The most challenging task is to evaluate seismic safety of these constructions and take necessary steps for their retrofitting so as to protect them from future earthquakes. Assessment of seismic vulnerability of existing building stock in urban areas would help in disaster mitigation and management by planning mitigation measures before an earthquake strikes. Seismic vulnerability is a measure of the seismic strength or capacity of a structure [14] , hence it is found to be the main component of seismic risk assessment. The review of the built environment for seismic vulnerability estimation is normally carried out in the light of earthquake resistance of buildings, past earthquake damage history & repair thereof, construction practices being adopted, building typology, seismic zoning of the area, building samples, detailed survey of selected buildings, and creation of database and its quantitative and qualitative analysis. The quantitative approach covers demand-capacity (DCR) computation, while qualitative procedure estimates structural scores for buildings and is known as Rapid Screening Procedure (RSP).