The 14th World Conference on Earthquake Engineering

Modern civilization has faced frequent devastating disaster in the last decade due to major earthquakes. Thus, disaster mitigation becomes significantly important in recent times. Like any other disaster the mitigation philosophy may be categorized either in reduction of the hazard or/and improvement of the performance against it. Unlike other common disaster like cyclone or flood earthquake can’t be predicted with confidence. Hence, preparedness against earthquake is the only option to combat this deadly event. Updating the seismic zoning map in the form of microzonation is essential for a better understanding of seismic risk. More importantly the performance of existing structures against seismic activity has to be studied to quantify its seismic vulnerability. The structural aspect plays a vital role beside geological and geo-technical considerations in assessing its vulnerability against earthquakes. The past history of earthquake particularly the damage associated to the structures is important input in seismic vulnerability assessment. Structural classification, motion-damage relationship and loss computation are the three basic parts of seismic vulnerability assessment. The factors influencing the vulnerability assessment in the context of the location of a city is also important. The salient features of Calcutta, an old Indian metropolitan city are discussed in relating to seismic vulnerability as an example. The importance of structural aspect in seismic vulnerability assessment, particularly for old cities with lot of aged structure is significant. Thus structural vulnerability against earthquake is significantly important in seismic disaster mitigation and briefly discussed in this proposed paper.