development of a comprehensive seismic risk assessment model for built environment

Abstract

Structural damage during recent earthquakes in India like in Bhuj, Chamoli, newlineKoyna, Uttarkashi, Killari and Jabalpur demonstrate the need for developing a newlinecomprehensive model for seismic risk assessment. The Bhuj earthquake clearly newlinedemonstrates that the vast extent of damage and the consequent loss of life newlineassociated with these events are due to poor construction practices. According to the newlineIndian Seismic Code IS: 1893-2007, about 60% of India s land area falls under the newlinethreat of moderate-to-severe earthquakes. Also according to Census 2011, the newlinenumber of houses exposed to such high hazards is almost 80%. Many cities in India newlinefall under the high seismic zones and have huge population and also there is a trend newlineof increasing due to lack of employment opportunities in rural areas. This lead to newlineuneven distribution of population across the country. Many people in these areas newlinelive in low to high rise building. Unfortunately these existing buildings are not newlineearthquake resistant, and they did not follow the existing building code. This is newlinebecause of poor construction practices and lack of awareness about earthquakes. newlineThese buildings are currently operational and need to be assessed and upgraded to newlineminimize seismic damage and improve life safety for future earthquakes. newlineAs a case study, Nanded Waghala, which is the second largest city in the newlineMarathwada region of Maharashtra after Aurangabad was chosen. The city is the newlinelargest urban centre and the administrative headquarters of the Nanded district. It is newlineknown as a holy place for the Sikh faith and it is situated on north bank of the newlineriver Godavari. According to 2011 Census it has a population of 5,50,564. This city newlinefalls under seismic zone-II (IS 1893-2002) in Penninsular India (stable continental newlineregion). This city is in the safe zone but close to Latur and Jabalpur. The earthquakes newlinein Lature (1993) and Jabalpur (1997) caused a lot of damage in the past. Many of the newlinetowns in the state have a number of recorded earthquakes in the last 200 years newline(records available from 1800